The seller seems to have one aspect of his description correct - the photo is actually of Jackson, which is more than what many Jackson photo sellers get right.
What I initially thought was silvering now looks like a blue-ish reflection from either fluorescent ceiling lights or daylight coming through skylights.
The word cabinet refers to a mounted piece, not the actual photo. I'm not sure why they included the word cabinet.
The main reason why I believe that this may have been produced after 1913 is because the image seems to be quite washed out and lacking clarity. This happens when a photo is taken of a photo...and then another photo is taken of that photo. This isn't an image from the original negative.