Great picture! I love the concept. I love how you did the sky too.
They don't immediately look like human arms because they taper at the elbow. Elbows are actually wider than most of the rest of the arm, especially when fully extended. Also, the shine on the skin threw me off. Makes them look like plastic or something.
But other than that, it's fantastic! I love the colors and the expression. And it's so cute too!