It's orthogonal to self indulgence; what defines that is the effect. And it's inherently subjective. I'd argue most religious animal sacrifices are self indulgent. Obviously, the believers think otherwise. (Nobody asks the animal.)
In this case, they absolutely made a sacrifice. But the main effect is the fact that they sacrificed something. The sacrifice didn't actually do anything. Contrast that with e.g. putting yourself at risk to save somebody. That is more than performative.