If anything that panel shows how Kidd is irritated with Luffy for not holding his end of the bargain, while he's out there fighting Big Mom, it's the reason they split up. Same with Law actually who was wondering wtf Luffy had been doing the entire time while the two of them were taking on Big Mom. While the rest of the cast is busy going "woohoo go Luffy!" These two are like wtf is this guy doing when we're busting our asses fighting an opponent on the same lvl. There's a clear distinction in tone and visuals here, it's clear as day.
If you think Kidd is worried about Luffy, refer to the chapter where he was laughing alongside Big Mom when he heard he died. The deeper he gets into this situation the more Kidd realizes he needs some help. Aka Kidd is still only worried about his own ass, issue is there are 2 Yonkou in their primes to deal with here. Heck he ideally doesn't want to be fighting with Law but he has no choice (a fact Law reminded him of at the start of this fight). Kidd's a stubborn POS but he's not an idiot.