Despite the fancy name, the feature basically adds editing to Vine, and that could be huge. So far, all Vine videos had to be shot sequentially, which made more complex videos more difficult. Now, you will be able to drag and drop to reorganize shots within your video, and also remove or replace clips with other clips. This could lead to far more involved 6-second vignettes made on Vine.
If you want to get the update just head over to either the Google Play Store or iOS App Store depending on your platform.