Miami phase corns are generally a rust red color (sometimes a bit more burnt orange) with a silver or gray background color. Yours already has so much orange saturation on the neck that there is no way I would consider it a Miami phase. A Miami locality corn is one that was collected from the Miami area and may not look as 'clean' or 'ideal' as a Miami phase corn (which has been bred over generations for that red and gray look), but will still mostly be a reddish and grayish corn snake. So unless you know that yours was field collected from the Miami area or is from parents from that area, I would consider yours a nice looking normal. Was it sold to you as a Miami?
This thread is a good read and has some pictures.
http://www.cornsnakes.com/forums/sho...d.php?t=135255