One very noticeable detail is that the “character” of one of the clouds is quite different in the time frames, spanning March 25 to June 5, this year. The morphology, color and structures of some of the clouds are quite different to those they replaced.
Anyone’s guess, but it seems that the structure of the clouds, and their relationship to each other, is related to the composition of the different cloud masses. If this is an atmospheric current, or eddy, creating new cloud formations, it’s a quite new phenomenon.
Jupiter's bands of cloud are extremely violent places, but they're usually consistent. This also raises the question of what happens to the massive clouds when they're removed from the upper levels of the atmosphere.
Hubble release images