The DM seems keen to point out that Catherine 'clutched a tissue' throughout the wierd photocall. I think they're trying to signal that the sunbeams really were not shining bright that day.
Also, he wore the same outfit in Rome, at airport and at photocall. Maybe like me he struggles to fine well-fitting trousers for his massive arse? Also, he CAN wear a face mask correctly when on his own in a car, but not when he actually needs to.