I noticed that the metadata shows crop dimensions that are larger than the maximum sensor resolution immediately after I auto correct the horizon and then crop the photo to realign itself. If I switch to another photo and then return to the one that was just corrected, the metadata crop dimensions change again and look correct.
Sensor dimmensions are useful; i.e. the JPEG camera will be contained in this space.
Thanks to these optical corrections, PhotoLab makes better use of this space.