Let's have a little photography lesson here.

What Dave has done is use a strobe flash for a fill light on a back lighted subject. The dark propellor did not expose the film even with the flash, so the background shows through except where the "Master Airscrew," in white, did expose the film. Also, against the wooden support that was lighted only by the flash, the blade shows clearly. The lower part of the blade, again with a lighted background, shows only the lettering.

And the nut, lighted only by the flash, does not show any movement.

No trick photography, just a peculiarity of fill flash on a rotating object.

Bill.