To make it more relatable/endearing? To encourage safe sex practices in the audience? To show the characters' own attitudes towards sex? I don't know, there are tons of different possibilities.
"It's not much fun if I'm the only one enjoying this." Yeah, WHY is he here, exactly? He eventually drops a token "fuck me", but otherwise, it looks like he'd really rather be anywhere else.
Sidebar; land-faring sharks are nothing new, but it never occurred to me that the otherwise aquatic animals could be hillbillies. lol
I'm a big fan of eyes. Its that part I look for first. The eyes of the panda are weirdly non-expressive to me. I see the positions and the 'movements', but most of the pictures make it look like they aren't even enjoying themselves. Which is silly, since they seem to have gone quite far out of their way just to get this futa dick.
Personally, i think its the overly thick upper eyelashes. It just doesn't look like it matches the blushing at all.