In #6b, his lollipop is on the table. He needs his hand free to slap his head in reaction to Dad's idea. If he was holding the lollipop, he'd bop himself. Or maybe his reaction is to Mom's remark about having no money to buy food.
In #8a, after making his debut as the Fat Fury, he appears unusually gluttonous, although he appears to be eating something other than dessert for a change.