Sure:
- Open a folder path via 'browse'. The folder I'm editing happens to be on an external drive.
- Choose an image or multiple images to add to a collection. Behavior is the same if it's a single image that's not selected, just a right click directly on the image, and single selected image or multiple selected images.
- Bring up the contextual menu and select add to collection. Can also choose remove from collection and get the same behavior.
- The thumbnails disappear and the message I mention above shows in the window, after a few seconds the thumbnails return and I can continue editing.