This is pretty cool.
A U-lock integrated into the bike design. It enables you to lock the bike to something, or for those just-nipping-into-the-shop moments, to render it un-ridable, by locking the steering.
It reminds me a little of those rear-wheel locks you see on classic bikes (my Pashley, or instance), with a huge score for convenience.
I guess there’s also the added advantage that any attempt to break it is likely to damage the bike frame too, so there’d be no point . . .