[less_less]

Oh huh, I was thinking the origin of the name "ristretto" was that espresso concentrates a certain amount of coffee in a small cup, whereas ristretto concentrates it even more: in this case it removes a cofactor of 8 and not just 4.

[oleganza]

Ristretto is a restricted form of Decaf, that is, specific to curve25519 and deals with a sign choice, while Decaf is generic for all cofactor-4 Edwards curves.

In other words, the joke around coffee takes a 90º turn with Ristretto because our first application was Bulletproofs where you need (among other things) a lot of orthogonal generator points.