As I mentioned in my first Worldview post, one of my hobbies is photography. I've been doing it for around 8 years now (it seems weird saying that, as it doesn't feel anywhere near that long. Makes me feel old) and I've used assorted different types of camera from basic point-and-shoots with no manual controls, up to DSLR+lens combos that cost more than my car (which is to say, about £1100. I have an old car).
However, despite the differences in technique when using these various cameras, certain important things remain constant: you are looking out fully immersed in the environment, with all your senses in use, feeling the world around you. The process of capturing a two-dimensional image in such a situation generally involves looking at a small rectangle onto which is projected said image, then waiting for the right moment at which to trip the shutter, freezing and storing that small slice of time.
Photography also has some common physical constraints across the board, though they vary in extent depending on the camera and lens (and film) used. Contrast can be a problem, especially on sunny days or in dark rooms with few light sources. Low light levels generally mean slower shutter speeds, which can mean blur due to camera shake or subject movement.
One of the biggest constraints is also the one that for many people inspires the photography in the first place: you have to actually be there in the right place at the right time (and looking in the right direction). Depending on the person, photography falls somewhere on spectrum that ranges from "snapshot of where I was" to "work of art" (and a picture can be both at once, but let's not complicate matters). In other words, for many people the photography is secondary to the experience of going somewhere, a record to remind them of the time. For some, the photography is the whole point of going to a place; the journey there is a relatively minor thing. And, of course, there are all the shades in between.
The point is, to take a photo you have to go to a place, and once there you experience it with all your senses. Naturally, people emphasise various sensory aspects differently - my brother, for example, is more likely to remember the sounds of things than what they look like. He is also a far better musician than I'll ever be.
And so we come to Screenshots, and given the above, I'm sure you can see where I'm going with this. Azeroth and Outland are virtual worlds (no, really), meaning the physical limitations of photography don't apply to them. In fact, to get the effects of long shutter speeds, contrast exceeding the limitations of the capture medium, or artefacts like film grain, these things have to be deliberately simulated. Limitations in camera focal length are arbitrarily fixed. Heck, even the mathematically perfect rectilinear projection used in pretty much every 3D game ever is a simulation of how things look in photographs.
Then of course, in WoW, you generally experience the world visually through a rectangle 17-24 inches diagonal, and aurally through either small desktop speakers, or through headphones. You cannot feel, smell or taste Azeroth. You are not there. Furthermore, the real world is really rather large, meaning long travel times, meaning time, effort and, often, money, is required to get around. As a result, you have a strong emotional investment in the place you are going to.
By contrast, Azeroth is tiny. Travel from one end of the world to the other takes half an hour at most, and is mostly a passive experience (sitting on a mythical flying creature while you go and make a cup of tea). When you do have to manually direct your avatar in the world, you don't get tired or out of breath, your legs and back and shoulders do not ache, and you can summon a mount out of thin air and move far faster than anyone on foot, or, if you're in Outland or Northrend, fly without the hassle and limitations of an aeroplane or other unwieldy real-life flying machine.
The upshot of this is much less emotional attachment to places in the game. You spent no effort to get there, so getting and being there means less. You don't feel the world anywhere near as fully, so it's less memorable. The latter point is compounded with the re-use of assets in the game, so once you've seen the caves in Elwynn Forest, you've more or less seen the caves in the rest of the Eastern Kingdoms, and they all kind of blur together into one meta-cave. Even within a zone, most of the landscape features will have few variations, so you end up seeing the same four trees everywhere you go in Azshara. The real world, on the other hand, is of course infintely variable – every place is totally different to every other place.
Lest I seem overly critical of the world Blizzard have created, I should make it clear that this weaker emotional attachment to places is can arguably be a positive thing for creating interesting screenshots. If you climbed Everest and took some pictures from the summit, those pictures would mean a lot to you regardless of whether they were "good" or not: you put an enormous amount of time and effort into getting there, and the simple act of standing on the summit of the world's highest mountain is quite achievement enough. In your euphoria and exhaustion your state of mind would be much less conducive to making good pictures, as you'd have so many other things to think about (even the simple act of breathing would require some concentration). As a result, you might well come home with what to anyone else look like rather generic pictures of some mountains. It's a common mistake of beginning photographers to assume that a picture that was hard to get, such as one taken from the summit of Everest, is one that people will want to see. On the whole, people don't care, and rightly so – all they can respond to is what's in front of them.
Since in WoW getting to places is so comparatively easy, you're much more free to concentrate on what things look like. Moreover, you are basically looking through a camera's-eye view of the world the entire time, so there's no disconnect between what you eyes see and what the virtual camera sees. There are far fewer distractions, too – although the world only fills a quite small portion of your overall field of view, everything outside the bounds of your monitor screen is fairly static, so your brain pretty much ignores it. With headphones on, music off and ambient sounds turned up, you can indeed become quite immersed in the world, just in a different way to how you are immersed in the real world. With the UI turned off ( [Alt] + [Z], if you didn't know), the world is almost pure visual stimulus, so your response to it is likewise going to be highly visual; you enter a peculiar state of mind where you are focussed near-exclusively on the appearance of that rectangle in front of you. So long as you are comfortable with movement and camera control in game, you barely need to think about such things, and it's only when the game forces you to concentrate on them, like when you get stuck on a low fence, that you ever think about them.
I don't know whether this state of mind comes as freely to others as it does to me. Perhaps my years of photography have trained me to enter it more easily. It's actually quite similar when I do street photography: senses other than sight are pushed to the back, and I see the world much more as shapes, compositions and contrasts. When I'm wandering around a zone in "screenshot mode", I try to dampen any thoughts about quests and lore and such, and instead just see.
When it comes to pruning, again, it is easier to separate the good images from the merely ok ones, as there aren't really any feelings attached to any of them regarding the effort involved to get them, since they were all easy to get (usually – there are exceptions, like if I was to do a Worldview on Ulduar or Icecrown Citadel or other high-level instance. I couldn't very well run about merrily taking snaps until the place was cleared first, which would of course require a lot of time and effort).
That's not to say it doesn't take a long time, incidentally – when you've spent two hours waltzing around Azshara pressing the screenshot key whenever you see something even a little interesting (occasionally multiple times with slightly different framing), you end up with 150 images to sort through and try to reduce down to 25 at most. Then they need to be arranged into as cohesive an order as possible so that they look more like a collection and less like a disjointed array of vaguely similar-looking pictures. Still, this point applies just the same to photography as it does to screenshots, particularly with photoshoots.
In the end, photography and making-screenshots-in-WoW (fairly rolls of the tongue, doesn't it?) are quite different activities. You still need the same sense of aesthetics for both, as for any visual medium, but the actual processes each have their own challenges and benefits.