Two pieces, one movement
The box is a single scored sheet. The server slides the slice in, folds the top over, and the side flaps tuck into each other — no glue, no tape, no second part. At a busy counter that speed is the whole point.
No glue, no waiting
Because there is nothing to cure or dry, the box is ready the moment it is folded. The self-locking flaps hold the slice in place by tension, which is all a triangular slice needs.
Why the blank is so simple
The die-cut is almost entirely straight lines, which keeps the cutting tool cheap and the scrap low. A slice box does not need vents or a liner — it is eaten on the spot.