Permissibility of General Compliments to a Friend's Photo of their Christmas Tree

Just wanted to ask if anyone knows, is it permissible to say "nice photo" or "wow" if they share a photo of their tree decoration if the intention is just casual respectfulness? Would that be imitating them?

I do not partake in anything else of wishing them or wanting to hang out with them for this or anything like that. It's just to respond to what they send and move along the conversation.