GANs in computer vision (part 5)

Pretty much everyone has already seen the examples of interpolating between two faces, so I really like that they show what happens when you interpolate PAST a face.

For example, they make an image of person C that is derived from person A minus person B (and the in between steps). I really want to play around with something like that but with custom faces, does anyone know if there are any sites where I can do it in the browser? Everything I've seen before just allows interpolation between two faces.