Apparently the 'poom' is crucial to the trick.
Swing out, turn around and get into a front balance position facing the platform. Once you reach the frontend, push the bar away and drop straight down (onto your front). Twist into the net.
I hesitated as to whether this was a 'Shoot Under' or a 'Shoot Over'. However, since you don't pass between the cables of the trapeze (as you do on an Uprise Shoot Over for example), I settled on 'Shoot Under'.
You can find out more about this trick in my books: