This is usually not a visibility or security issue, but a native-specific limitation or configuration.
In Native Mobile, images behave differently than in web. The most common reason is that the image is not being loaded through the correct widget or data source.
First, make sure you are using the Native Image widget, not a web-based one. Web Image widgets do not work properly in native apps.
Second, check the data source of your Gallery. In native, data should come from a nanoflow or a supported source. If the image is not fully available on the client, it will not render.
Another important point is the image entity. It must be a specialization of System.Image, and the association between your Location and LocationImage must be correctly retrieved.
Also verify that the image is committed, the user has read access, and the file is actually stored (not empty).
If everything looks correct, try explicitly retrieving the image in a nanoflow before rendering the page. In native, the data needs to be available on the client side.
If this resolves your issue, please mark it as accepted.