While the Angled Fore-Grip (AFG) proved quite popular despite essentially changing the way many shooters hold their weapon, there were some changes that Magpul realized they wanted to make once it saw wide spread use. Rather than forcing the hand to assume a vertical grip, the AFG positions the hand in a more natural manner.
So what are those changes you might ask? As you can see from this photo provided by Magpul, almost everything has been improved. Essentially, it works in the same way as its predecessor but it is slimmed down. Additionally, the angle is shallower and it is sleeker to accommodate items mounted on side rails such as lights. Finally, this aspect of the design will allow it to fit additional rails that the original AFG had issues with. The AFG2 should be considered an enhanced design and the original pattern which is now referred to as the AFG1, will no longer be produced.