How Do You Lean in Rainbow Six Siege?

How do you lean in Rainbow Six Siege? Leaning allows a player to see around corners without exposing their entire body to a potential attack from an enemy. Given Rainbow Six Siege's emphasis on lethal, tactical gameplay, this technique can prove invaluable. Here's how to lean in-game.
I did some extensive perspective testing in Siege (and a couple of other games) to put together some actionable advice on positioning, leaning and stance choice in Rainbow Six Siege. Here it is.https://t.co/xBBOGDUA6P pic.twitter.com/emKIgYlj5z
— Rogue-9 (@RogueN9) June 27, 2019
How Do You Lean in Rainbow Six Siege?
Leaning is valuable in multiplayer, but it's an essential objective in the Situation mission Tubular Assault. That mission provides no tutorial on how to lean, making it frustrating for players outside of the know.
Leaning in Rainbow Six Siege is only possible when aiming down the sights of your weapon. Once you've scoped in, pressing "E" on PC will toggle your character's right lean. Pressing "Q" will do the same for leaning left.
On console, the lean buttons are R3 and L3 for leaning right and leaning left, respectively.
Players can walk around while leaning, but the lean is best used when checking a dangerous corner or holding a tight angle.