F-22 - Nozzels do not protrude, they are highly angled on the ends and protected from IR signature, also made of very advanced material to further reduce IR signature:
T-50 Nozzles protrude far back where their IR signature is not hidden or protected. Ends not angled, round all around. IR Missle magnets.
I have no doubts that the T-50 has good radar stealth...I do not think it will be as good as the F-22 in that regard...and from what I see with my own eyes, it will be far less stealthy from the rear in IR.
What you see on the F-22 are the movable thrust vectoring nozzles. They are not for hiding the exhaust signature.
The F-22 hides it’s directly aft exhaust heat signature in the internal engine design and by mixing cooler air with the exhaust, and with a longer than necessary let pipe, which evens out the temp of the plume.
Exactly the way the T-50 hides it, as you can see. The protrusions you commented on are likely for reducing the heat signature aft.
Both jets hide it from the side and front the same way as well. By locating parts correctly to block the engines from view.
Only a very old heat seeking missile system would need to see the engine exhaust to detect the plane anyway, and both jets will easily defeat such.
Modern missiles don’t rely on detecting the engine’s exhaust plume.
Thanks for the pic. Is it possible that the T50 shown does not have the full stealth superstructure over the engine as it is a test model not necessarily the final article?