Pictures By Alan

The white line rising to center frame is another rocket about to explode. It looked like they spun as they rose; that would be natural since spinning a rocket is an inexpensive and effective way to stabilize it. The spin accounts for the ripples on the right edge of the white line; the rocket was alternately shooting sparks more to the left and more to the right as it spun and rose. It's visible on the left edge too, but since the sparks were being blown that direction by the wind, it's less clear.

Photographs of fireworks can be very nice, but they don't really look a lot like what one perceives while watching them. The rocket rising appears here to be a column of sparks, for instance; but in real life it is clearly a single, brilliant point of sparks, rising rapidly.