The dark hexagon directly below the canard looks to me like a perforated panel that let;s additional air into the jet intake. The one in front of it, right behind the edge of the intake, could be some kind of assess panel. All the flush panel joints appear to have the stealth zig zag. This suggest the benchmark for stealthiness is very high, and a fundamental design consideration right down to the most detailed design. I would venture to guess J-20 goes much further to maximize radar stealthiness than the T-50
why does the fit and finish around the side missile bays look so much worse on the 2016 than on the 2013?