Django model for real estate
As a rule of thumb in programming, "there are only four numbers": zero, one, two, and "many".  You have seven photo fields, which means that you should just treat that as "many".  Not only is that an unfortunate artificial limitation (someday there will be a listing with eight photos, and you won't be able to accommodate it easily), it's also a pain to write code that uses your schema (you either have to copy-and-paste code six times, or use variably-named identifiers).

What you want is a separate table for photos, to support a one-to-many relationship.