Napping at the office is something I wish I were able to do (I can’t really fall asleep ‘on demand’). I believe it’s common in Japan to sleep while commuting due to their hostile work culture. In the southern European countries it’s customary to have a mid-day nap, though I don’t know if you’d have at at the office.

Also: Just because they’re symbolising ‘office’ with a desk and chair, that doesn’t mean they expect you to sleep there. But if they showed a dedicated rest room (bad choice of words), no-one would think ‘office’.