The geometry of the visor and the part above it very much does suggest it isn't just a "simple helmet".
It is consistent with what would be expected for an HMD. However, interestingly it seems like there are no IR LEDs used for tracking on this helmet which is visible on J-20's HMD, suggesting that it may use a different method of tracking helmet position.
We know that AVIC does offer other HMD designs as well.
Question also is whether this HMD (if it is what it is) may be a strap down design intended to operate with existing PLA helmets, similar to JHMCS family.