1. A shadow is not possible unless he was playing on Endor with the Ewok band and they were outdoors with Endor's 7 suns shining all over the sky.......
2. Maybe, just maybe, in the interest of remaining competitive and unique in his chosen profession, 'ol JHB didn't want everyone knowing his secrets to his sound and there aren't any documented explanations of what that ring is.
3. Is it possible he may have cut out a second reso head and installed it inside of the intact reso head. That is what it looks like to me. Or, it is a scarring efffect from the floor tom always scraping at the reso head there when he stacks his drums up......., or he has a flashlight inside his kick drum and it is creating this effect. He does that in case the power goes out.........Or, it is a thin layer of super glue he trowled on around the outer 3" of the reso head to hopefully someday have a bunch of guys sitting around their computers, that he also envisioned years ahead of the technological revolution, so that they would keep posting pictures of his drum kits. Along with being everything herculian concerning drums, JHB was also a legendary visionary, rivaling Nostradamus, and he even guessed the outcome of a Magic 8-ball six times in a row correctly once!!
toodles
Drumhack x-mas3The Bandelectricitx-mas2Burger Kin