[Rooster61]

It's frankly hard to tell much difference when put into the same color scheme. Granted, those minute changes represent MASSIVE shifts in the arrangement of matter throughout the nebula, it just doesn't look that way from this far away.

[hnuser123456]

The nebula was created by a supernova that exploded about 1000 years ago, and the images were taken 25 years apart, so it's about 2.5% bigger in the newer photo.

Besides the overall expansion, some of the wispy cloudy features seem to have changed more qualitatively, some of the curves have shifted shapes and positions in ways more complex than simple expansion, due to magnetic effects.