How do you guys feel when (or if) your spouse sends you pictures of their kids?

My S/O has sent me the same picture of SD twice. Once last night and once just now. He said he said he sent it once before but I only received it two times. When he sent it last night I didn't respond right away because I was visiting with my mother and my phone was across the room charging. When I did respond it was because he sent a follow up text message asking if I had received the picture. I told him I had but that I didn't respond because my phone was across room room charging. He just said "o okay" and changed the subject. Fast forward to just now. We had a tiff today on my lunch break so we didn't talk. Typical S/O behavior, he sends texts unrelated to the tiff because he's fishing to see if I'm still upset. So he sends me a text informing me about a shooting at LAX (we live in Los Angeles). I respond "sad". I don't expect a response. Half hour goes by and he texts me a pic of SD and it's the same one from last night. I've already asked him if he just sent that or if that's just the one he said he sent last night that I never got, finally coming through. I haven't received an answer.

Nevertheless, this isn't the first time he's sent me pictures. He has sent me multiple pictures of SD through the course of our relationship. I don't always mind. Some were relevant to conversations we were having and other pictures were random. It's the random pictures I'm curious about. Like the recent pictures. He sent them out of the blue. I'm wondering why he does this. All I can speak on is how it makes me feel. I feel like this is an extension of the fact that his world revolves around his daughter and he wants mine to also revolve around her. I feel he's testing me. To see how I react or what I say.

Do any of you experience this? I don't think it's a good idea to ask him why he does this. I feel like a jerk because when this happens, I find my eyes rolling and I really just don't care. The picture he sent me today and last night she's standing there in her Halloween costume eating a lollypop. Her face isn't painted and the costume is just Princess Sophia costume. I've seen her wear it before. It wasn't the one she WANTED I know two characters she wanted to be this year and neither one of her parents got it for her. I was at target with my S/O and we saw one of them. I said he should get it because it was his year to take her trick or treating. He alluded to the fact that her mom was getting her one, whatever, no big deal. My point is, she's not doing anything spectacular in the pictures and I feel like he wants me to just gush over it but I can't. Should I just suck it up and find a way to pretend to enjoy it when he interrupts my day with a random pic of his kid? I generally just give one word answers like "cute" or "cool". I feel this is sufficient but I feel like he wants more than that.