What's That Thing on Top? Williamsburg Top & Side Edition

Things at the Jackson Foundry at Manhattan Avenue and Jackson Street in Williamsburg are coming along fine as the photo shows. In this case, the thing on top sort of blends--at least better than many things on top. However, our real question in this case is, what is that thing on the side? We can live with the former, but we're soooo not feeling the latter.