Yes. The auxiliary intakes used to be Su-27-style louvers, but were later replaced (or rather covered - I presume they're still present, albeit invisible) with a mesh screen. I'm not aware of a good close up, this high-res photo is probably the best I can do:
View attachment 50810
It's a RCS reduction measure, I expect.
The mesh screens might be either for RCS reduction, for foreign object ingestion protection, or both.
I also note that the latest prototypes do not have "visible rivets" unlike what we used to see in initial prototypes. Now that RAM coatings are applied. This has been apparent with prototype T-50-11 (511). Also, if you look at the assembly pictures of modern Su-57s they use a lot more composites in the fuselage panels. Take a look at these for example.
The first flying prototype.
A more recent prototype in assembly a little over a year ago.
There are a lot of people who think the Russians or Sukhoi are idiots. I have always said for people to wait until the actual production version is in service before they pass judgement on the aircraft. Just look at the Su-27 prototypes and the actual mass production version. It is like a totally different aircraft. Did they expect this process to be any different? The first prototypes were to test the flight control laws. Not to have maximum stealth. Supposedly the aircraft also lacked strength in the internal airframe, they found it during flight tests, and had to be redesigned. Until I see the mass production version, with the Izdeliye 30 engine, I will not pass judgement on the quality of the aircraft.
For example, it might be that the frontal RCS will be reduced not just with mesh screens, but also with composite materials in the cold section, i.e. frontal, fan blades in the newer engine. Until we see the final version in service there is no way to properly estimate the RCS.