Multi-Person Disguise

It works because the bulges in the trench coat certainly are normal and not the body of another person.

A Multi-Person Disguise is a Terrible Disguise used by more than one person to make up a figure meant to look like a single person. It usually involves three people: one on top, one in the middle, and one on the bottom. The top stands on the middle's shoulders and the middle on the bottom's. The top wears some kind of headgear, such as a fedora or baseball cap, that is commonly paired up with sunglasses to further protect the top's identity. The middle's arms are used for the disguise's arms and the bottom's legs for its legs. Although the disguise as a whole visually makes no sense, it still fools Figuratively Blind People into believing that the disguised people are really one person.

There may be a point in the story at which the disguise falls apart when the people forming it lose balance and topple. If the disguise fails in front of somebody who it's meant to trick, like a security guard or police officer, it's time for the people who were disguised to Run For It.