The state of the car (interior, exterior, cleanliness) should always be recorded at both check-in and check-out. Depending on the type of rental, this will be done either by you or the owner, using the Getaround app or the paper contract.
Make sure to thoroughly document any pre-existing damages or mess so you can avoid being held responsible. If necessary, feel free to take additional photos with your phone. Keep them for at least 30 days after your rental has ended so you can contest any cleaning fees or reports of new damage.