In addition to the lighting it's imho also the "wobble" distortion, artifacting and what i suspect is some movement from the camera pod.
There's loads of higher res pics of the nose around (Albert is just my go to source for a quick look), i just wanted to show that this particular modular panel has been on the W14 from the beginning of the season and that it looks different depending on the angle/lighting of the shot.
It appears to be a single piece together with the two upper inner FW flap pieces which slightly changes depending on the FW config, i personally don't think any "mechanism" would be needed to achieve the desired flex, just thin walled carbon - i might be wrong, of course.
Either way, there are no "huge reinforcements", there is no "clearly" visible change to that part and even if Merc had to stiffen it up any reinforcement would arguably happen on the inside as to not disturb the airflow.