What did the analytical engine look like?

Answer 1

That cannot be said exactly as it was never built but some guesses can be made from the drawings of the various sections: mill, store, printer, etc. The exact layout of a finished machine can only be guessed at.

The largest part of the machine would have been the store, consisting of 1000 columns of 50 digit wheels each. Assuming each digit wheel to be roughly 1 inch thick and 3 inches in diameter, this would have stood maybe 5 feet tall and occupied over 250 square feet of floor space.