It seems as if rotated images also affect the entire enclosing bounding box. Comparing the supplied pdf-file in mupdf with evince/xpdf indicates that there is something fishy going on in mupdf.
Created attachment 5357 [details] simple-image.pdf A minimal example illustrating the issue, compare the rotated image to the left in different viewers.
*** This bug has been marked as a duplicate of 690674 ***