Idea: Before and After – More Reveal Directions

It would be nice to have the dragable reveal element could be top to bottom instead of just left to right. This would be great for content that is arranged from top to bottom already, for example. Another idea is to have the reveal element start in the top-left corner of the image, and reveal the image from the top-left corner to the bottom right corner, to give a triangular reveal ux. Of course the ideal would be to give us the option to have the reveal start from any side or any corner, and move to the opposite side or corner for the full revelation of the after image.

What do you think about this idea?