Part of image beyond focus plane with Nikkor 55mm is acceptible to me but is not as Leica or Zeiss. On your image (to poster) is also visible sharp edge and limit of bokeh field. This is however acceptible and I would classify micro 55 mm (current) as among the best (not the best) nikon lenses, and for far and for close. Also that lens is far better in just anything than the lens Kertesz ever could dream about.
you know, there was a time that this level of nitpicking would have been thought rude, because it talks about your predilection for equipment, not the image. The point it is, it was taken of a flower, with a Nikkor.
You don't say it should have been taken of a schoollbus, you don't say it would have been better with a Zeiss.