Photo date: February 16, 2017. Photographer: Mark Mahin.
One of the most astonishing things about the mysterious orbs I photograph at Grand Central Terminal is their uncanny tendency to often align exactly to lines and edges in the station: things like architectural lines, edges of windows, the edges of flags, and the edges of window frames. See here for about 200 examples. My photos don't always show such alignments, but I do get them much, much more often than I would expect to see by chance.
Below we see an example. The right part of the left orb is aligned to an architectural line, and the bottom part of the right orb is aligned to a black edge on the window.