Thicker eyeliner is a facial feature setting for Face 4 that
the character in question doesn't appear to be using in the Endwalker screenshot.
Here's a comparison of my character, for clarity:
I agree with Aurumis's conclusion, but to your point, the eyeliner 'facial feature' was not made thicker -- though it was certainly altered in other ways. At least on the eye option I'm using, I appreciate that the additional eyeliner's lumpiness was smoothed (for the most part lol), but that's about all I can say for it.
You can also see the way his profile's been changed in these comparison shots I took previously:

(The annotations are about the shape of the nose and lips. The upper lip, in particular, is now pressed flatter against the face in DT, making it unusually uneven with the lower lip, unlike the previous model. The shape of the nose has lost the feline sleekness it had previously as well.)
And gods, I miss my thicker eyebrows (which is also a facial feature option my character's using in all screenshots).