There seem to be at least two kinds of analysis boards here at Chess.com. In online games, the analysis board always opens to whatever the current position is on the main board, and it's the same size as the main board. In Chess Mentor and similar puzzle contexts, the board is always at a fixed size, and it always opens to step 1 of the puzzle.
I find these last two characteristics of the puzzle analysis boards make the Chess.com user experience feel lopsided and inconsistent. It's very annoying to get stuck at step five of some problem and have to get out the analysis board, only to discover that it's necessary to make all the moves for both sides leading up to the current position; both time consuming and error prone. I also really dislike the small size in contrast to the "huge" size I set for the main boards.
I didn't really feel bothered enough to complain about the puzzle style of analysis board until I decided to go all in and upgrade to top tier membership. You don't get access to all that much for more than twice the price, and I really expected the crème de la crème out of the super premium Chess Mentor. The analysis board it's saddled with makes it feel kind of cheap and lackluster, and I do find it significantly disappointing, if not really a deal breaker.