To reconnect with the 1970's music from my now-distant youth, I was watching the Alan Parsons Symphonic Project concert [recorded in Medellin, Columbia] and saw lead vocalist PJ Olssen make that shape a couple of times during their hit song EYE IN THE SKY, specifically during the lyrics, "I am the eye-in-the-sky, looking at you.. I can read your mind."

As he formed that diamond shape, he first had it over his heart then later had his hands above his head and "aimed" it at the audience, sweeping it from side-to-side.

I thought then it was kinda' odd... here, see for yourselves:

[link to www.youtube.com (secure)]

BTW: it was such a good concert I immediately bought the DVD, because good music never gets old... unlike the rest of us!