Be creative. Be appealing.
This thought just crossed my mind today. Where do you put your villager pictures? Do you store them all in a museum? Do you have shrine rooms? Do you store them and decorate your house with just a few?
Right now, I have a museum room with pictures of my villagers that I got on April Fools', and then I have the pictures villagers have given me randomly decorating my house since there's fewer of them.
I have two active towns with Dream Addresses. (Their codes are in my Signature below. Applewin has several updates with different codes. So, one visiting should refer to a date, like the most recent, they want to use.) I arranged the pictures in my second town, ACNLpics, in alphabetical order specie after specie: the cats, the dogs, the goats, the horses, the kangaroos, the ostriches, et al.
Every human character has the ten villagers on display in their homes in Applewin. Here is a picture showing eight of the ten villagers of Applewin (Julian and Phoebe are not shown but are nearby) in Mayor Jill's living room:

In ACNLpics, the villager pictures are presented on display stands in museum-like atomosphere human houses. This picture shows Applewin Mayor Jill having a Dream in ACNLpics in the living room, of all the frogs, in Jason's "Pets"-themed house:

All I can suggest is that you use your imagination. Present the pictures in a manner that you find relatable and appealing. You, most likely, won't regret doing that.