Under Canon Wireless, this is just a way of enhancing 'pre-flash' sensing when a Speedlite is behind an 'Ezy'-style softbox. Sensor orientated away from the softbox. This augments environmental pre-flash bounce off walls & the ceiling. The speedlite is held in a metal 'Stroboframe' pattern cold shoe clamp. With these the metal is cut-away to clear the speedlite pins - and so avoid shorting. The photo shows the upgraded ball & socket adaptor which I did not like and have since changed to a D type Ebay adaptor.

A test of a paper softbox design I found. All it takes is four sheets of regular letter paper, and three paper clips. I think it worked pretty well.