Step 1: Ctrl + F
Step 2: Click brush icon
Step 3: Draw on the canvas
Step 4: Click search icon
And then the browser will find the items that match the outlines on the page and mark them as such.
This feature is useful when searching for a character that cannot be typed, but only if the user is able to use the mouse to draw the desired pattern without a touch or stylus.
Maybe in the future it would be nice to add a brush with a different color, or the ability to find a particular frame of a GIF.