scaffolding as protection
over-sidewalk scaffolding is erected to protect people on the sidewalk during repairs and construction that may be occurring in the building, or on the face of the building. It's ubiquitous in NYC and usually comes in the form of a 1-story scaffold covered by substantial lumber and surrounded above head-level by plywood barriers. Only the bottom 6 feet is open scaffolding. The second picture only hints at what the situation looks like, though NYers would recognize it in a minute.