New York City (painting)
Art historian Susanne Meyer-Büser announced in October 2022 that the artwork had been displayed upside down at the Kunstsammlung Nordrhein-Westfalen for decades.  The other artwork New York City has a denser group of lines at the top of the painting, which were said to represent the sky, while New York City I was displayed with those lines at the bottom.  A picture of the painting in the artist's studio also showed the painting with the denser lines at the top.  There is no signature on the canvas. This might have added to the confusion.  Mondrian had not signed the work, possibly because it was unfinished.