In their defense (and for the sake of conversation), I want to point out that publicity photos and aeroplane glamor shots are nothing new, anywhere. They are made for real aircraft and hypothetical aircraft alike, and often fake ones as well. Because I don't know what the official press release said, I have nothing to go off except the linked article. If they are simply advertising the aircraft and noting that flying low can reduce the chances of being detected by radar, then, well, wecome to combat doctrine from 50 years prior (and then a few years earlier still). Furthermore, being able to carry a payload is rather essential to being of any use as a frontline combat aircraft, as it or some future version of it is advertised to be...
One must also consider, if they are indeed serious about pursuing this project, what the design criteria of the total project is. Consider the ubiquitous F-16, found about everywhere Western governments exist or where resources exist which Western countries like. The F-16 is an unstable, supersonic fighterplane which is able to fly due to a highly sophisticated electronics suite which was among the first of its kind... in fact, it was the first of its kind. The avionics package on the fighter allows it to attend to just about any modern fighter mission, and it has proven the ability to do so in this facility within the rigors of combat.
Now consider if the F-313 is a mock-up for a tech demonstrator, which may be close to full size or full size. The aircraft has been stated to be stable (and lacking any advanced FBW), looks to have thick airfoils which would be helping in that advertised short-field capability, and not a whole lot of room for avionics. So... This at least proves one advertised lie so far - it's nothing like an F/A-18 Hornet, except for maybe one thing: this could be being developed along the A-4 Skyhawk or the Q-5 Fantan... an attack plane. Granted, not an attack plane of Hornet caliber, but a simple, subsonic attack fighter which needs no radar. With GPS or INS, simple, low-cost avionics provide all the functionality the pilot needs to navigate and drop unguided ordnance. Being a bit more stealthy than your old F-4s, F-5s, and F-14s, and being targeted by countries which have all the latest gadgets of death, you might just want a cheap LO fighter should somebondy decide that you must be invaded next.
In conclusion, before someone actually finds the official press release, I will argue that if the F-313 is intended to become a working design within what has been shown, it will not be a modern "superfighter." From what has already been echoed from the official press-release in reporting articles, it cannot take down modern fighter craft not only due to avionic/stability/structural issues (all are related in this instance), but due to aerodynamic issues as well, which I discussed in my prior post. No, it will be an attack plane maneuvering very little and staying out of the high-alpha flight regime. It probably will employ a small afterburning or even non-afterburning turbojet engine, make use of a small internal weapons bay, and rely on large amounts of off-the-shelf hardware which Iran can either manufacture locally or get relatively easily from outside markets. I assume their command staff recognizes that it would be impossible to win a war of attrition with their potential attackers, so why attempt to match them when that goal cannot be attained? This is a product of a MAD policy of sorts - Iran will lose a conflict should it begin, but they will attempt to get a few jabs in before they go.