When your forehead and/or chin are roundish are longer than your nose. Making the person's face look like it has been mashed in the middle like a potato.
No words to explain, too beautiful; but we will try our best: The process of lifting your chin up and sinking it back into your neck causing a chinless appearance. Potatoing is the verb form of potatoface.
"It looks like Rory has a potato face on."
"No, he's just fat"
Potato face is when you take a photo and you have multiple chins or fatrolls that could be avoided by finding a flattering angle. They may not be there all the time but in pictures its hard to ignore.
That girl is so pretty but she has potatoface in all her photos. Youd think shes fat.