Most 'character breads' are made by creating the character out of ropes of colored dough. For example, you'd start here with four ropes of dark brown dough. Two of those, you would then wrap with a layer of uncolored, white dough, and put them next to each other to make the face. The two others get pinched along the top and arranged on top. The final layer of green dough has to be kind of gently pressed into place around the ears.
After baking, when you cut it crosswise, you get the panda pattern, just like you get a spiral pattern when you cut a jelly-roll.