Europe and Asia generally require photographs, America generally requires no photographs.

It’s more granular than just ‘Europe’. Having a picture would be pretty weird in Ireland, say.

In the UK, too. I've heard lawyers advising a policy of blanket-discarding CVs with attached photos to avoid any possibility of discrimination during screening stages (though I don't know whether this is because of a specific law or just their judgement regarding minimising risk).

That is Problematic on so many grounds. I am surprised the EU hasn't banned that on discrimination grounds.

As a matter of fact the "standard" EU CV (so called Europass) has the photo "field" :

https://europass.cedefop.europa.eu/about-europass

(with a recommendation to check whether it is allowed in the specific destination country):

>Add your photo only if required. Check local provisions in the country where you intend to send your CV.

As someone with a visible 'disability', I wish it would.

In Portugal I have not received any without a picture on it. It does not help.

It does not help what? How would you know?

Because I review those resumes for our company and, as others have said here, it adds bias even if you don't want to. That does not help.