Okay, visiting the headbangers reminded me of other Photographing the Photographers images I have in my files. Tom--the Fishing Guy had a funhouse mirror. We encountered one in Edinburgh on the Royal Mile.
Imac had two shots of people bending back to get a shot of family in a touristy spot. Here is my daughter doing the same at Mt. St. Helens a couple of years ago.
BTW, you will find the other headbangers linked in my sidebar. Give them a visit.