What does "roll-cut" mean in this recipe?

A roll cut is when you cut a long vegetable on a diagonal, roll it 180 degrees, and cut again, so you end up with a triangular or trapezoidal shape (depending on how far you space your cuts). If you zoom in on the eggplant in that picture, especially on the top left side of the bowl, you can see how the two sides are slanting opposite ways. See this video for a tutorial: https://www.youtube.com/watch?v=QmDXM5YNPm0