If you haven’t used info-beamer yet, here’s a quick summary on how everything is organized: There are packages that provide functionality. You create setups based on those, add configuration and then assign such a setup to one of many devices.
The permission system that got recently added allows you to invite other users into your account and to assign permissions to those users. It is possible to set permissions based on (for example) setups. This would allow you to restrict invited users to only edit some of the setups. What is not possible is to restrict what can be edited within a setup. As a simple example: If you only have a single setup showing five images and assigned that to all your screens, it’s currently not possible to restrict a user to only be able to edit one of the five images.
In your use case, there might be another way of handing this: You can prevent the user from editing the setup at all and only allow them to overwrite the
slide1.jpg asset. That way they can change the content (by uploading a new
slide1.jpg image) while not being able to edit anything else.