I'm not sure if there are different etiquettes for different local regions. But for my area, all areas are exclusively just around the contiguous businesses' buildings themselves.
If the building is multi-business, where each address is leased to a separate company, the area is placed around the entire building and not assigned to any specific business. Unless the building belongs to a company and there are other businesses inside, such as a Walmart with a McDonalds inside (which would be an area for Walmart, and a pin for McDonalds).
- Here's my local Walmart, which is an area with other business pins inside: https://i.imgur.com/9V3gOoz.png
- Here is my local mall, which is an area for the mall itself, with pins for the businesses inside: https://i.imgur.com/TCQZfxZ.png