Request fanart critique

UPDATED LINK

This is a photobooth picture BTW.
The first panel is Riza sitting up with a formal smile while BHayate is leaning in closer to the camera. I wanted him to lick the camera but didn't know how to draw it ;3;
The second panel has Riza with a more nonchalant/curious. She's supposed to be more informal by each panel. BHayate is doing something underneath; as you can see, you only see his tail.
The third panel, we see BHayate was putting on a mustache (don't ask) and shows it off to Riza. Riza is still sitting back thus BHayate is smaller compared to the first panel.
The last panel has Riza now warmed up and more informal in the photobooth they're in. I tried to make her eyes more smaller...like in anime/manga, y'know. Blushes and a hug is added to exemplify the more relaxed feel Riza has. We can all thank BHayate if you want.

Updated to now ask for critiques as a whole...especially on coloring.
Thanks!
Thanks to envythejealous for reminding me to talk about the art!

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