Here’s an updated version:
To update the minimap, you need to constantly draw to it in “on game update”. (1)
To reset the minimap, you need to reassign it in on game update. (2)
To show the minimap, you need to get its image every time it changes (in on game update). (3)
If you leave out step 2, then you’ll see a trail where your sprite moved which is sometimes what you want:
If you change the game update interval, you’ll get dots across a map which is what I originally used the minimap for:
