[throwaway049]

Small differences such as placement of pictures on walls can be enough to tell rooms apart. As for what good? It can help linking up to other evidence such as hotel security cameras. It's (I assume) not useful to ID the room, but is useful to ID the hotel so that future surveillance can be planned. I am sad to be reminded that I once read a notice in my hotel room in Manila which asked me to verify the age of my guests and note that the age of sexual consent there is 18.

[croon]

If you can get a reasonable timeframe for the photo (even a month or more) and you know specifically which room it should be trivial to get a list of occupants of that room during the time frame. Combing through tens of people should be manageable, and it should be less.