Answering the phone if a company calls you for an interview can often give a very good idea of their race/nationality and gender too, but somehow we seem to be fine with phone screens for interviewing people. Perhaps because there's typically not a recording of it?
Agreed - so let's stop pretending that if someone sends in a picture with an application it should somehow automatically be scrapped. I understand the 'lawsuit prevention mode' that some companies may adopt, but realistically, the type of people who would sue over this issue will sue whether a violation actually occurs or not. And there's generally ample signals beyond a photo that indicate something 'discrimination worthy' (age, voice, gender, name/ethnicity, geography or lack thereof, etc).
In fact, uncommon religious names can often give away the religious background of the candidate. Someone named Mohammed is likely to have a Muslim background, someone named Nephi a Mormon background, someone named Siddhartha a Buddhist background, and so on. While the person so named may no longer practice their birth religion, a person who'd discriminate based on affiliation with a given religion probably doesn't care.
I've googled potential candidates, and that usually tells you a ton about that person. As far as I know, it's pretty common practice. But maybe HR doesn't know much about that yet...