Flash zebra is, first and foremost, in the eyes of the beholder. When discussing this at great length several years ago, it was proven quite soundly that there is no consensus among the community as to what a flash is beyond simply a particularly attractive juruense.
That being said, this little guy displays a pattern that could be described as more of a speckling or spangling than the typical stripes that we see on very young jurs. It also has a very unusual amount of the lighter coloring. All of these characteristics are things that people normally point to on a 2' fish that they feel qualify as an exceptional enough specimen to be labeled a flash zebra.
Though, when we come to the end of it, any jur grown out long enough will develop flash zebra colors. The lighter parts of the pattern on a jur are the base color, and like many other fishes, will fade as they get larger, thereby improving the overall appearance of the fish.