Oscarus

Just having a nice selfie  

It was one of my favorite moments, when watching the episode. They are also people too

Exactly! 

That's what I mean. 

Champions are humans too! Very strong, powerful, talented humans... but humans nevertheless! And humans can make mistakes, not be always correct, and do various activities that stray them from the perfectionist. 

They can even feel negative emotions like anger, frustration, depression, regret... or seemingly not positive, like consternation or uncertainty. 

While Iris, Cynthia and Diantha were doing selfie, Steven WAS concerned that Leon would crush Alain, which Lance noticed that. That is because Alain is Steven's trainee (sorta) and friend, so it's natural for the heir of Devon to be worried about his junior, who was about to face current World Champion. 

In the mainline games, the only non-rival Champion who shows a variety of typical-for-common-humans emotions is Alder, which actually saddens me. Technically Leon does too, but before the actual battle with him, his emotions are basically joy, responsibility, being undefeated Champion, and panting with directions. 

People can trash at anime as much as they want, but they can't deny that there are two things anime does better than the games - battles, and showing emotions of the characters.