I started liking this series the first time I saw Misuzu fall on her face (in a comic moment, of course--I'm not an ogre). A dog named "potato" was the clincher. After that I didn't care that all the characters' faces looked like they're inflatable.
If the Ikeda Kazumi tag is correct (I assume it is) then this isn't actually canon Air art. Ikeda Kazumi works for Kyoto Animation but she didn't work on Air (she was the art director and character designer for Kanon and Clannad). So it would make sense that this art looks kind of... weird.
Ikeda Kazumi is correct because her name is credited, but this is still official art. She was not the main character designer for Air (that is Aratani Tomoe), but she did do animation work for KyoAni on that series. Other KyoAni series also have official art from animators other than the lead character designer (there's some official KyoAni Clannad art that isn't illustrated by Ikeda Kazumi, for instance).