Well, actually, it’s not a baby carriage… it’s a pug carriage. You can tell by the little paw on the side.
Apparently this pug is something of a neighborhood icon in the Embarcadero area of SOMA. He (she) has a spinal problem that causes him to drag his hind legs when he gets tired. So when he goes walking, it’s in a pair of boots, and when he gets tired there’s a ‘coach’ waiting to take him home.