Witch img diminsion columnn is that, there are two one that take the diminsion from the meta data. (faster) or the other that read
One is the dimensions stated in the metadata.. "Picture (EXIF) dimensions" and one that checks the actual image file "Picture (IMG) - Dimensions"
I guess the you show the size from the ExiF metadata.. This can be wrong if the image is resized and the program did not update the metadata tag with the new size.