Dashed line = safe area. Keep faces and words inside it; the photo still fills to the outer edge, and that extra 30 mm past the cut line is what lets the print template sit anywhere on your design without a gap. The dashed line never appears on the download. On hearts, the short black tick below the tip marks the centre line for matching the shaped print template in Photoshop; it sits at the outer edge of the trim-away area, so it never shows on the finished block.