What Mysterious Buttons actually do? (RectTransform,Rectangle & R)

Hello guys!

My question here is about these two mysterious buttons here. I have no idea of their purpose, there’s no tooltip and there’s no names. Unity Docs has no info on them.

What do they actually do?

75923-screenshot.png

I’d imagine the OP has probably figured this out by now, but for any fellow Google search travelers, this is answered here: What do the dotted-square button and R button on a Rect Transform do? - Questions & Answers - Unity Discussions