Isla Bowen
It was the first day of the busiest part of the year--that last month before Hogwarts started up, when Britain's youths (and their parents and/or guardians) descended on the shops of Hogsmeade and even shops like Lochrin's got extra business just because of the sheer volume. It would go back down to normal levels again come September, as it always did, and Protego probably shouldn't treat the whole thing like going to war, but he was nonetheless standing by the front window of his shop, coffee in hand, squinting dubiously out at the early morning foot traffic on the high street like a general preparing for battle.
The shop wasn't open yet--hence the coffee--but he had full view of the street, so when a knock came at the door, he at least knew who it was before he unlocked and opened. "Good morning, Isla."