This is only a wild guess but I think this mirror is supposed to help prevent cyclists and pedestrians from colliding with each other, in what is a traffic-free environment.
Or maybe it's to help very tall people to comb their hair.
Or perhaps it was stolen from a fairground's crazy hall of mirrors.
Or possibly it's on loan from Tate Modern.
Or...
Take up cycling in Waltham Forest, and enter a world of limitless, intriguing surreal wonder.
Langthorne Road E11, by the bridge over the A12.
