If my information is correct, Public Affairs is actually prohibited from photoshopping or otherwise altering the content of a photo, except to do basic things like tweek the colour and contrast levels.
It is the same for the RCN (from my observation). The oncoming OOW takes the watch once they indicated that they understand the situation and have the watch. The notebook gets signed ending the previous watch. Legally, it is all on the new OOW at that point.
On the CPF? Most cabins were never supposed to have more than one occupant for any length of time. That went out the window quickly when the reality of crewing came into play.
Also, with most cabins having settees/fold up bunks, I am not sure how that would work.