I'd love to hear from folks as well...
The only system I've tested on is a newly built PC MAME running a Ryzen 1200, Radeon R7 250, CRTEmudriver, and a K7000 Aracade monitor.
Works as in the video for me ... I can change the "skin" to any...
NOW, if you're using a layout other than 640x480 you will need to change the size of the images to stretch to match your layout...
...though now that I think about it, I probably should have just used transparent PNG's rather than ones with black backgrounds... that way even if someone doesn't scale the image to their theme size, it would appear correctly (albeit smaller surely)....
Thoughts?