Couple thoughts on it:
-There’s a real legal issue in terms of photos as there’s an issue of discrimination. Personally as an employer, I’d worry a little if asking for photos opens up a huge can of worms.
-If he/she wants to have a photo, I’d include it in the resume as part of it. I’ve seen that before.
-For this one, where a phone interview is upcoming, I’d say skip it. Seems weird. If the idea is to make it feel personally, maybe include a link to his linkedin profile in an email message and make sure there’s a photo there. I bet people click on it