Is that a tiny house on the roof of an East 57th Street tenement?

Ever since the concept of the penthouse became fashionable in the 1920s, New York City rooftops have hosted lots of creative domicile styles. There’s a pink fairybook-like cottage on the top floor of a prewar building on East 52nd Street (once home to John Lennon in the mid-1970s), for example. And what would the East Village be without this homey cabin with a brick chimney perched on the roof of 105-109 Third Avenue, the walkup with Kiehl’s on the ground floor? Usually these rooftop houses sit on the top of already pricey apartment buildings. So it’s always been a surprise to me that someone at some point seemed to have constructed a little house on top of a five-story tenement just past First Avenue on East 57th Street. See the shingles and a skylight on the slanted roof, an awning over the front door where a window likely once was, and two air conditioners in the front windows. The little house is set back, creatinf a terraced front. (That sign by the door says “Mets fan parking,”…