Admin can set the maximum number of images per listing that can be uploaded in the submission form for four scenarios:

1. Free Submission

Define how many images users can upload for each property listing from the front end in Theme Options -> Submission & Membership -> Property Submission Page -> Maximum number of images per property 

2. Membership based submission 

Here there are 2 possibilities.

Free Membership

You set the number of images from Theme Options -> Submission & Membership -> Membership Settings -> Membership -> Free Membership Images

Help article about membership submission

Paid Membership packages 

You set the number of images in each membership package you create

4. Paid submission (per listing fee)

Help article about paid submission

Define how many images users can upload for each property listing from the front end in Theme Options -> Submission & Membership -> Property Submission Page -> Maximum number of images per property