Yeah, age I can understand. People usually list their college degree along with the date of graduation, so you can usually make a good guess about their age.

But, I have no idea how you gather gender or marital status from a resume.

Most names are gendered. Can I tell 100% that Jane is female from the name? Of course not, but then I can’t tell with certainty that someone who graduated in 2011 is ~30 either.

It’s fairly common in my experience for CVs from European candidates to have marital status/other family information (and often a photo!) on them. I don’t know why and I just ignore it.

Very true. I suppose I worded my earlier comment poorly. You can generally infer age and gender from one's name and education dates (of course, not always). But the point I was trying to make it that this would not be explicitly on there, particularly marital status. But looks like even there I'm wrong.

Pictures on resumes? That's a new one for me.

Yeah. It was super weird the first time I saw it on >80% of resumes I was screening for a director position in Europe. I asked my HR contact over there and she didn’t seem to think it was unusual at all.