Thanks for your document, it does not work. the heart Mask in Hype should be the heart shape with fully transparent, but there should be some color in other area. By this way, only the content under the mask layer will show up.
I think there might be a way to do that, but I have not tried. For example, create a Heart shape with some background in Photoshop or AI, but cut that heart shape to be transparent, and then paste that image into Sketch, and then copy SVG code from Sketch, and then paste that code into Hype
Do you think it is possible?