When a block like sand or gravel falls the item frames that were attached to it float for a few seconds before dropping off.
Linked issues
duplicates 1
Attachments
Comments 4

Similar how?

The frame holds an item, like a chest right? When you break a chest it drops the item, same as when the frame drops. The reason they can't assume your in creative is because in multiplayer, you might be deleting something that a survival player has.
I understand now, thanks.
This is not a bug because it is similar to breaking a chest in creative.