I think that photo is a bobcat, guys. Not just because of the docked tail (who would dock a cougar tail anyway), but because the ears show a coloration change (as does the tail, which would not be true of a docked cougar).
Note how drab the coloration on this cougar's back is:
Now look at the ears, tail color, and general length of tail on the one photographed in the Smokies:
Finally, look at the white color patch on the back of the ear. Here's a bobcat in a zoo:
Now here's the best shot I could find on the internet of a cougar ear seen from the same side.
I believe there are likely to be cougars in the Smokies, but I don't think that's one.