This is actually the very first time someone made a hands-on video with the prototype!
ProAV TV writes:
Recently, Panasonic announced their move into the Full Frame mirrorless market with the S1 and S1R. We were very lucky to get hands-on in one of the first showings of the camera outside of its announcement at Photokina. We don’t know much more than what was announced at Photokina, but this was a great opportunity to get a feel for the ergonomics of the camera.