I agree with Ian too
Drivers won't know instinctively what it is or what it means which fundementally renders it useless, worse than useless if people use it without arm signals.
I'm not really convinced by it anyway though, surely it would need more clearance away from legs to shine such a wide angle pattern. Then at junctions where street lighting is often pretty decent, it'd need to be very bright to stand out at all and being floor lighting it'll be obscured by the bike itself, other traffic and will be a narrow angle to see from a distance. Also probably means more wires on the bike.