The F-313 has appeared before in 2013, when War Is Boring pointed out that the jet was too small to carry its announced weapons payload or even fit a normal sized pilot.
Business Insider showed the footage to a senior scientist working on stealth aircraft who asked to remain anonymous due to the classified nature of his work.
"Some parts are laughable" as far as radar signature goes, the scientist said. Specifically, the downturned wingtips reminded him from something out of "Star Trek," while he said that vertical or near vertical fins on the plane would light up a radar.
Additionally, because the plane has been made in Iran, the scientist seriously doubts they have the engineering processes and expertise in place to manufacture a stealth aircraft, where minute details need to be perfectly lined up to baffle radars. Iran has been under sanctions for years, prohibited from buying the kinds of components needed to build advanced stealth aircraft.
Writing at Vice's Motherboard, journalist David Axe pointed out that the F-313 - which does not fly in the video - has its tire pressure stenciled on the outside of the plane, and it's way too low for a full-sized, real airplane weighed down with instruments and fuel. The scientist told Business Insider that tire pressure "takes away all doubt that it's a fake."
Still, some experts say Iran could attain somewhat credible stealth aircraft in the near future, as China's J-31, an F-35 knockoff, nears production.