Foam Peaks

I was drinking paulaner salvator, mixing drinking out of a glass and bottle drinking. I poured about half a bottle into a glass very vigorously, about 4in. of head, and noticed it was two different shades. There were dark peaks, or mountain shapes, and all that was above it was a lighter color. The glass was being reused without rinsing, filled with the same beer about 10 minutes prior. What would cause this? The peaks were a rough triangle shape, and 1/2in. wide and 1 1/4 in. tall, they dissipated in about 4-5 seconds progressively as the head decreased.

Any explanation considered. I am going to attempt to recreate this.

Perhaps there was some sort of sticking to the glass?

I heard that someone saw the virgin mary in a piece of grilled cheese once. That being said i totally believe you.

I am going to attribute this phenomena to a couple of things. First hefe's are going to be carb'd more than a normal beer so by vigorously pouring the hefe into the glass you created a very large head on the beer. I also seem to be able to produce something like this with a warm light bodied beer (such as a hefe or an apa), if the bottle of beer had been sitting on the counter while you drank the other beer for the prior 10 minutes it could have also attributed to this.

I know there are ways to formulate beer that would consistently do this, I also know that pilsner glasses such as Google Image Result for http://www.my-own-beer.com/lgpilsnerset.jpg
seem to cause these types of heads on beer more so than other glasses.

This thread could use a picture...