I think a picture is totally irrelevant. Who cares what I look like as long as I am qualified to carry out the job in question competently?
If I were on the tills at Next, I would hope the customers would be more concerned about how polite I was and that I offered them a friendly smile rather than how gorgeous I look. Including making sure I give them the right change, not how much make up I have on.
I suppose for some people as well, asking for their photo on a job application won’t be kind to everyone’s confidence.