The slider fourth from the top is to increase or decrease the size of the graphic. The bottom slider will dictate how far up or down the cup the graphic is placed. Depending on where the graphic is placed on the cup will determine how much warp is added.
When it looks how you want it, don’t forget to hit apply. This will make the curved rectangle go away and the warp will be applied to the graphic. I forgot to hit apply and just moved my svg to the top of my screen and cut it. It did not affect the cut, but the outer box is a bit distracting.
Because the design is already warped, there is no need to cut up the transfer tape and spend forever lining things up. Take some care with placement, ideally measure down from the top of the cup to the top of the design. In Silhouette measure from the top of the curved rectangle to the top of the design. This will ensure the placement is correct for the curvature of the svg. I skipped this step, and my cup turned out alright. However, I can tell it is not completely straight.
For the full tutorial check out the video below.