User blog comment:FTWinchester/Holy Terror/@comment-24461572-20140124131714

In season 4 the Angels also appeared as whispy smoke. The blinding light and the smoke are 2 separate visual depictions. Humans are still being possessed by Angels, the visual depiction has changed. When Gadreel was expelled by Sam and he returned to his previous host the blinding Angel light was there as well as the whispy smoke which was already established in S4.