Designing Your Mesh Event: How to Create a Great Immersive Experience

Great question. I don't believe there is documentation on Purview's impacts on Mesh specifically. However, Mesh does not do anything "special" with respect to its files that are stored in the SharePoint associated with the collection, so any policies that are applied associated with Purview should generally be respected. While storing your event assets in your Mesh collection is very reasonable, I don't think there is specific value in using the Site Assets folder. That folder is optimized for content used on SharePoint Pages. While it should work for Mesh content, it will not automatically ensure permissions are matched to people who join the event like it does for SharePoint Pages. I would recommend you either use the existing Documents Library or create a Mesh Event Content library for that purpose mostly to avoid confusing and mixing content that is associated with Site Pages in SharePoint and content that is used for Mesh. Importantly, when you customize an event by adding Images and Videos using Mesh Objects, it is up to you to ensure the right attendees have access to the content when they join the event. If they do not have access to any content elements they will see an error message instead of the image or video itself, but will still be able to see other content they do have access to as well as be present with other attendees in the event. Here is where any policies associated with Purview should be respected, so if you are not allowed to share a file with a specific user due to Purview they will get that error message on the Object in the event.