Today I learned about a feature in our new Gallery app: notes. The feature is best described using pictures.
One of the old Project Pokémon banners I had lying around, uploaded to a private album
When your mouse is in the giant dark-gray area, there's some buttons. One of them is the Add Note button.
The Add Note Button
Clicking the Add Note button adds a transparent, resizable, and movable rectangle to the image, which comes with a text box that lets you add text.
Once notes are added, they can be read by mousing over the image.