And yet I thought I was the only one who noticed :D I have just the same opinion as you!!!
Yeah, he became cuter, his eyes are bigger
It's called the uke effect. Sometimes characters will look more cute the more uke they become. I don't know if mangaka do it on purpose or what.
I read an article saying that the author was unsatisfied with Yano's first look which is why it changed. It was intended to be a oneshot initially so maybe they hadn't given it enough thoughts.
I guess that's it.
Um, don't you think Yano's face looked different in the earlier chapters? He has a more feminine face now,not that it's a problem but I think it's really noticeable.