The Snipers Edge Attack Triangle is basically a simulation of a defending player

It has a stick blade and two skates (forming the triangle).

 The intent of this aid is to simulate the presence of a defensive player and to train the player with the puck to be able to stickhandle and manoeuvre the puck away from the stick or between the defencemans feet. In reality it is more of a simple puck control exercise because real D moves when you skate near them.

It certainly can be useful for puck handling and skating drills,  especially if you use a few of them in one drill and set them up in the portions of the ice where a puck carrier can expect to encounter resistance.