Comment 14 for bug 1643706

@hackel and @bhjolly - yes, there are limitations in what strict confinement allows. We have transitional interfaces for home and removable-media that allow snaps to access the user's files and hotplugged media. If you mount outside of these areas, snaps will not be able to access the data. Today you can workaround this be choosing a mountpoint under /media or bind mounting into it.

Very soon snapd will be able to leverage portals for arbitrary file system access (this will hopefully be in 2.32). The major toolkits like gtk3 and qt5 should then 'just work' and use the portals file chooser instead of falling back to the traditional file chooser.