Comparison of structure of Elephant Trunk Nebula (IC1396) in Cepheus and the Rosette Nebula (Caldwell 49) in Monoceros. The radial scale of the ET Nebula is about 3 times that of the Rosette (1.3 deg), partially explained by ET being less than half the distance from us (2600 ly).
Despite differing colours in the image, the composition, structure, and apparent cause are all very similiar.