I’m an IC shopper but I also do pickup orders for myself while I’m out and about. Usually the store shoppers says “store 8 shopper 2” but I’ve had it say random names like “John”. If the order in question was filled by an instore shopper it would have told you “name of instore shopper” is shopping your order and “name of driver” is delivering your order, where you would see a new name and photo.

There was a post either here or in the r/InstacartShoppers page that had a very similar situation. There was a reason that person doesn’t have their own account either they were deactivated or couldn’t pass a background check for whatever reason