If your dogs know how to take things somewhere, they could take a tissue out the box and give it to the person. If you ask the retirement home they will have a list of the music that they listen to at set times, if thats the case then even just a few tricks alongside that. That way residents who can see well enough and take it in can enjoy, if not they can still get their usual music session.

I know that sometimes they do pass the ball games etc in sessions for early stage dementia and so on but you might not want to go for that one

I agree that for some just petting the dog and reminiscing will be good