Extreme randomness

This was very weird. One afternoon in Exeter town center we were walking along and passed something very unusual. There were a group of people (probably about 10), all with white hoodies which said "Time & Light" on the back. They were walking around in circles, corssing over the high street. At one point I saw a middle aged man get a mirror out and point it at someone else across the street. This was obviously some signal, as the guy on the other side (just a kid) got out a mirror too and signalled back. I tried to take a photo as I was walking past, but it didn't come out very well. If anyone knows anything about this then please tell me what it's about!

Update: I just remembered that they all had 2ft white + red striped sticks. I'm not making this up!