It seems that Firefox from-image is nonstandard (from-image in specification is only defined for image-resolution). And default behavior of ignoring EXIF rotation seems correct according to this weird specification:

>Note that some devices will "tag" an image with some metadata indicating its correct orientation, so image viewing software can do the necessary transformation themselves. Due to legacy compatibility restraints, Web browsers are required to ignore this data by default. A future level of this specification is expected to have a value that applies the metadata-specified transformation automatically.

IMO EXIF rotation should be applied always, and any CSS rotations should combine with it, not override.