The first image was taken at 6.03pm. Notice how close the comet is to the adjacent star.
As time progresses the stars appear to rotate
around the pole star, all of them following
concentric circles, and so they always appear to maintain the positions relative to each other.
However, in the second image, taken nearly 2
hours later, at 7.57pm you can see how the
comet's position has changed, and it is now further from that star as it follows its unique path.