It wasn't a shop, it was one of several pictures taken by a local to Naples who noticed a sudden influx of camoed, Detroit licensed plated cars on the road. While out near a Harley testing ground, where the cars were seen originating from he snapped some pics of one of three cars with a massive cowl.
The pics were later confirmed by MM&FF, 5.0, and several other reliable sources that the car was indeed a test platform for a 5.0 Cammer with a prototype intake manifold. This intake manifold was later seen in a smaller form on the Boy Racer car now residing on the front page of Stangnet. Other accounts especially the one from MM&FF pointed to a production GT motor which was being debuged in the new Mustang platform because of the possibility of a 5.4 transition, as well as the fact that they only had 6 prototype cars at the time 3 of which were on car show tour.
Colletti has gone on record as saying he is going to go with some iteration of the 5.4 for the Cobra....but what we have no clue. I will seriously doubt that we will see a dry sumped 5.4 Aluminum block twin screwed GT motor in our mustang, but then again we just might get a dumbed down version of the motor. Possibly even a cast block with the standard Eaton on it. A modest and underated 400 HP would be nice eh? What ever it is, I think Ford realized they made a hit with a factory SC cobra, and have no reason to revert. Shelby is back so hell we may even see some cars with his name on them, and specialty motors of his choosing.
One can only dream, until we are fed some more info.