How do playlist updates work?

This article explains the process that happens when you ‘save changes‘ to a playlist. 

AbleSign is designed with reliability in mind, so your device will download the videos and images in your playlist to it’s local storage (rather than stream them across the Internet). Using this approach, your device can always play it’s content regardless of the state of Internet connectivity or others factors at the time of playback. 

Downloading of your video and image files happens silently in the background. To ensure a seamless transition to the new playlist, your device will continue displaying it’s existing playlist until all the files have been downloaded. Bear in mind that for video files, this may take some time.