This argument never seemed to hold any water for me. Ok, most cases of "discrimination lawsuit" were because people were discriminated negatively, not positively. Wouldn't discarding the resume _because it has a picture_ have the exact result that the person discriminated person complained of? If that is so, it seems NOT accepting the resume would open you to lawsuits, not accepting it. Yet, I don't see a lot of fuss being made about job-seekers claiming discrimination because of CV pictures out there.
Of course, it's probably easier if you can prove that you discard _all_ CV's with pictures anyways. But have some exceptions go through and you might get screwed.
Regardless, if you don't have a clearly stated policy of dismissing CV's with pictures, it just feels like an asshole move, frankly.
That's exactly why it's done.
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.