This is a video shot with the Voigtlander 25mm f/0.95 Nokton lens at f/1.4 throughout. It shows the video 1 to 1 crop mode, EX. TELE CONV. in the menu which creates the movie by restricting the lens that it shoots through to the 1920 x 1080 size of full HD video. This gives you 2 lenses in one. The normal focal length, in this case 25mm and an approx. 2.6x increase, in your lens range for video. (For stills it just reduces the size of the image recorded to 1920 x 1080 pixels.) So for the Voigtlander its a 35mm/full frame equivalent of a 250mm f0.95.
This isn't a digital zoom, its the same quality as the normal size lens would provide. Amazing feature, and as others have said Panasonic don't seem to be making anything of it. Apparently if you use the 100-300mm zoom at the 300mm end you get the 35mm/full-frame equivalent of a 1500mm lens!!!