This was a somewhat imaginative & creative act on a library statue. I suppose it was technically recycling, given that the bicycle helment was actually cracked and of no further use as a protective device. There may be some mundane justification in as much as May is bike to work month.
Still, the officious one in me says this is just a step away from valdalism. If adding a bike helmet was good, perhaps one might think changine the paint scheme would be better. No.
(And in fact, as soon as person in charge realized the statue had value-added wardrobe, person at work was asked to remove it.)