I spotted a project named “Octogon” (sic), and its like sister project “Triangle”, both published by user rosenhayden. “Octogon” contains two blocks, the first drawing one octagon and the other drawing one square. There’s a “size” variable with an input slider. Whenever the green flag is pressed, the full screen is mysteriously redrawn with octagons and squares - I don’t have a clue as to how this works: no hat blocks anywhere to be seen.
Can anyone explain? (rosenhayden perhaps?)