Mirroring can take several forms. Camouflage is part of this Chara's suite of survival skills.

Oh, the other does copy it! Chara is something they can only pinpoint as along the lines of pleased, when that happens, enough the momentum continues. They try to mimic the smile too, to keep the match, but even though it comes easier than usual they somewhat fail - it's too wide, and too stretched.

They don't notice, and with a little daring lean a little to the side. Will that happen again?

(Children of many species play at skills they'll use when older.)