Explanation of Cheesy Poof's Quick Turn

[EthanJF123]

Cheesy Poof, team 254, posted their 2014 code. Looking at it, I'm not able to understand how or what purpose their quick turn function works. I understand that holding a button and turning allows you to take a sharp turn at a high speed, but can someone explain in more detail how it works.does team 834, Robobees, use this implementation. Thank you.