No. A rolling shutter deals with different parts of the sensor being exposed at different times within one frame. It generally requires a much faster object (think airplane propeller or light with PWM). This is effectively multiple frames captured normally and a mistake in the algorithm stitching them into one frame.

No, the difference is too large for it to be rolling shutter. (not sure if the rolling shutter is even vertical or horizontal). It seems like it takes a short video and stitches together the sections with the least motion blur in each frame.

Rolling shutter could in principle explain this, but it’s probably too fast to capture these three poses which must be temporally rather far apart.

Not probably too fast - definitely too fast. Rolling shutter occurs over a single read-out of the sensor, so she'd have to have held all the three poses during the 1/100th of a second or so exposure for it to be possibly related to rolling shutter.

Completely valid nitpick.

No. Rolling shutter should typically be too fast for a shot like that. Much more likely it's a result of 3 photos taken at slightly different times and automatically composited. Appears to be a well known effect.