Otters love to swim around, floating on their backs, wiggling in the water like little derps~
I imagine that this pose is either him lying on his back in the water, or on a bed or something. So since it's summer he's swimming. :3

This art is SO SO cute, done in one of   jdpuppy's streams. He's a great cartoony artist, so if you want something just as adorable as this you should follow him! He's also a fantastic fursuiter, which is just as good a reason to follow him if you ask me. ^^