Nonsense. The rocks in Central Park are shaved in the same direction.
If massive ice sheets occured regularly, the rocks would be sanded down to nothing. The odds that the erosion was caused by a recent event 400 years ago is nil.
I wrote, "A scraped rock (roche moutonee)--- there are hundreds of them in Central Park. These are all scraped, gouged, abraded in the same direction" --- which is just what you said. One one-off occurrence as far as I know.
I didn't say anything about multiple "massive ice sheets occurring regularly," or "recent events 400 years ago". Perhaps you're thinking of somebody else?