Except without the glass top. Or perhaps glass with a very dark tint so that it looks black, but with sufficiently bright internal lighting you can see through it.

The easier and more likely version would be to make the computer fit in a normal desk drawer. Prefer that to a 1U on account of fan size as another commenter mentioned, but being off to one side instead of the whole desk surface has the benefit of not making the whole desk chunkier.