Harry was not going to be intimidated by Goyle, even if he was all tall and muscley. Harry had years of Auror training on his side, and he was one of the best in the department. So he just stared back at Goyle, refusing to back down.
"Well, I'll just go back and say hello then." He gave Goyle one last look, one that let him know he'd be watching him very carefully. "I think she's ready to check out." He gestured to the lady and the pygmy puffs, who was standing impatiently at the till. "It's not good to keep customers waiting."
With that, he headed out back to say hello to George.