I can't find any information about this little parklet online, but I think it's safe to assume it was the work of Mr. Henry Stern.
UPDATE: It was indeed named by Mr. Stern (thanks, Gigi!), and for a very Sternish reason: one of the adjacent streets is Garfield Avenue.
Is this similar to the Hair of the Dog?
You assumed correctly, Matt! http://www.nytimes.com/1998/03/15/nyregion/on-sunday-nomenclature-thy-name-is-henry.html
Great article — don’t know how I missed it!