Cats are solitary hunters, dogs have to be in a pack to survive. Cats are social with one another for fun when they feel like it. Dogs have to be social with their pack all the time or they will die. People are most like dogs in this regard.
Cats tend to stay in one place, dogs migrate wherever the hunting is good.
Your girlfriend’s cats are freaking out because they’ve been moved. Unfamiliar places are very stressful for cats. Also the whole place will smell like you and they will feel insecure until it starts to smell like them. When they rub their faces on things, they are scent-marking it (humans can’t smell this). Hopefully they are fixed, because otherwise they will spray to scent-mark and you can definitely smell that.
To them, the scent of the new environment says – “this territory belongs to someone else, so you’d better lay low if you want to stay alive.”
You can try a product called “Feliway” which has some pheremone that calms them down.
Anyway, give them some time and don’t try to play with them if they dont’ want to, don’t grab them to pick them up or anything. Just let them figure it out, eventually the place will take their scent and they will feel more at home.
Cats and dogs are a lot different, each can be fun in their own way but each can be a big pain in the ass too.