Crossfade Function in SampleEditor - What Is It For?

Is there a tutorial or document describing how the “Crossfade” function in the sample editor is supposed to be used? It doesn’t seem to allow for actual crossfade looping, but performs a destructive edit on the selected sample region, for a purpose I don’t understand.

If you check the “Undo” checkbox on the lower-left side of the sample editor, no action will be destructive.

The crossfade function copies the selection, mirrors it and paste the mirrored part to your selection using the center part of your selection as the y-axis. Whatever does not fit into the selection is indeed being discarded.
The crossfade also applies a few db’s downramping to the output result.

I mistakenly thought that this feature would add a little cross fade to smooth out my looping points, too. Obviously, it doesn’t do that.

Maybe it’s some sort of oldschool tracker or sampler effect. All I know is that it seems to take a reversed copy of the selected region and mix it in with the original copy. It sounds weird on a long sample or a drum loop (which can be cool), but the effect, especially when it is used on a narrow loop region, can also be practical, like how it will smooth out a sustain loop for a note that was dropping off quickly.

Someone who knows similar sampler effects or who understands the underlying code could chime in and give you a better answer.

Edit: Oops. vV already gave a better answer.