Actually, there are two Clouds in the first pic... because if you look carefully, the second pic is a blow up of the top-left hand corner of the first, with a little extra added on. It does indeed look like a magazine shot where someone has combined two pics (one smaller, one larger) to show a demonstration.
And I can think of a number of places that look similar to that screen... Ancient Forest has much the same style, as do the secret Materia caves and the Northern Crater. Even the Mythril Mines has a similar kind of style.
While most FF7 scenes do have an almost overhead detached view, some are *meant* to have greater depth and use a more 'flashy' angle. One of the best viewable instances of this is the bridge leading into Corel; Cloud's running all the way into the screen. Nibelheim on fire (while in Jenova's illusion in the Northern Crater) is another example, as is certain parts of Sector 8 during Disc 3 (particularly the second screen in, with the big girders in front).
The major reason you often don't get things that close to the camera is because it's really difficult to deal with that kinda stuff if you need the room to scroll as well. It just doesn't look right. Plus, it can also obscure the player's view of the characters. In the beta scene provided, both of these problems are avoided; the room is only one screen big, and the leaves are at the top while all the walking area is at the bottom.
Remember. The discovery of the Key of the Ancients isn't meant to be a normal scene; it's meant to be similar to the secret Materia caves. If you look at it from that point of view (and if you assume that it *is* a beta of such a room), then it fits right into FF7, easily.
Really, I don't see the problem. It's obviously not a scene in the finished game, but it could've fit right in easily.