Images

I am a Rise novice, but the image you show is cropped when displayed as full width. It is centered vertically inside the block with the top and bottom clipped off, so you lose the wave edge. The image is responsive, so if you resize your browser window, you will proabaly notice that the botom wave edge becomes visible as you shrink the browser width and the image shrinks to fit within the display port. Rise does not seem to offer a way to align the image to the bottom, which would maintain the wave edge.

A possible alternative is to insert a small transparent image as the main graphic and then edit the block style, using your wave-edge image as the block background image instead. You can then edit the cropping and overlay properties for the background image (overlay = 0%, crop image to only lower 50 to 60%).

The tradeoff is that the background image is not responsive. It will not resize as your browser window changes size, but the bottom edge will remain visible.