It's just a dream sequence at the start. Try to not look at it too much and just head for the bathroom, it's not very long and you should be ok after that. Obviously be careful, nobody wants you to endanger your health. Nothing happens to the MC and you won't really miss anything by skipping through it. The MC is just remembering finding his dead "guardians" and the terrible smell.
Hopefully the Dev does something about that for photosensitives like yourself.