These 'videos' (GIFs) are a sequence of frames (i.e., a sequence of still photos). By running through a sequence of photos/frames you see the motion being captured in the 'video' (GIF).
In this case each frame/photo during what was considered the 'load' was duplicated. This gives the appearance that the 'loading' was twice as long on a relative basis. It makes the active swing portion, which did not have duplicate frames, look twice as fast on a relative basis.