Films are NOT videos. Do not mix the two. Films are raw flight and code data. The film viewer opens up a "kernel" of the game and applies the data. Basically, if you somehow changed the 3D model of the La7 in your game to be the shape of a UFO, you'd see a ton of UFOs flying around in your MA films.
If you changed your default skin, that skin would previously show up instead of the usual one (before the addition of the game including the skins into the films).