Why does Dora wear bellyshirts?

Dora, from the popular children's show "Dora the Explorer," doesn't wear belly shirts. She typically wears a purple, short-sleeved shirt with a bright yellow backpack strapped across her chest. Her outfit is designed to be simple, colorful, and easily recognizable for young viewers.

It's possible you're thinking of a different character, or perhaps you're thinking of a piece of fan art or merchandise that depicts Dora in a different outfit.