This is definitely one of the cutest extras we've had. I'm a bit sad we don't get to see what's really on the letter, but the fact that she framed it while it was still closed is wholesome in its own way. I can't help but wonder if she secretly read it and put it back, but... I doubt it. She's almost too pure for that.
The smallest thing though would be Kalego, and Purson, also sharing the same black nail polish that Iruma is using. Azz getting it for him is expected, but Kalego actively agreeing that it's good and using it himself is pretty adorable. They don't tend to show his softer side in such a simple way.