I recently had this question from a student in my online Master Class:
What is “picture frame” under Passcode Lock?
Your iPad is also a digital photo frame. Picture Frame mode (Settings > Picture Frame) lets you choose images, select transitions and set other options for slideshows. You can use your iPad as a digital photo frame even while locked. You need to turn the feature on first. Go to Settings> General> Passcode Lock> Picture Frame. Now your iPad’s Lock screen will show a small flower icon in the bottom right corner. You can tap it to start your slideshow without having to unlock your iPad.