I don't know if they have some computer way so that everyone who logs in has one of their covers show up or if it was chosen, but still it's a cool experience.
2nd from left bottom row on the bottom right Nook. Big left Nook in the back, top row, 1st image on the right.
Update: Most of you have probably been there and know it's not some weird computer program that manages to insert a cover that belongs to the person who's logging in. It's Summer Horse in the image for everyone.