Passport renewal

I'm just about to renew my passport in preparation for my planned overseas holiday this year (first in 4 years!) and just had a browse through the "do's and dont's" of application when I came across the requirements for the passport photo.

I was quite amused by the one on bottom middle which is "unacceptable" because he is wearing tinted glasses AND is smiling! I understand the glasses part, but a photo can be rejected if the person smiles!?!? How strange.