I am so sorry about the death of your wonderful husband, Mermaidhair. You must miss him so much and 12 months is no time at all in which to deal with grief or come to terms with things, either emotionally or practically.
Indeed your MIL has lost her son, and my heart goes out to her, but I don't think you are being unreasonable. I would have no problem at all with open displays of grief, but what you describe would, at best, certainly be awkward or irritating and could, at worst, become an unhealthy ritual, which your children observe from the sidelines for years to come.
I agree with others that you should remove your photographs ... the ones you want to kiss, touch, hold and talk to ... to your room, meantime. I also agree that you should make copies for your sitting room, but I don't think you should put these back on the side table, to perpetuate this ritual. Maybe you could hang them on the walls. Perhaps not all together, but in small groups, so ... for example ... in one area you had one or two pictures of your dear husband alongside some pictures of your children, in another area maybe one or two of him interspaced with other family members (dare I suggest MIL?
), and in yet another area a special photograph of you and he together.
You could involve your children in where to hang them and how to group them and then ... when MIL came ... not only would the photographs be harder to kiss in any ritualistic way, they would also be a talking point and a focus for the relationships and loss that you all share. Hopefully, the grouped photographs could even bring MIL's focus around to your children, too.