I periodically see this and can't explain it. I think sometimes it might just mean some church system isn't working at the moment. But, if you see it consistently, that may not be the issue.
I have sometimes seen this when moving new people into our ward. I think there are sometimes problems with photos when changing wards. If it doesn't go away, I just take new pictures.
Your theory that an admin hasn't approved it is another good idea. I've wondered if that's what happens when someone's records move in and they have unapproved photos from the previous unit.
Do you have any idea if these people with the photo placeholder moved in to your stake recently? Also, I have a vague recollection that you mentioned in another post that they reorganized stake boundaries in your area somewhat recently? If so, that would mean that a lot of people changed units in some form and could give credibility to problems with photos when changing units.
If you see a bunch of these and your units were reorganized recently, this could be a great opportunity for a church developer to debug the situation and solve the problem. I don't know how you'd get that to happen; maybe your stake president would have to bring it up with CHQ. Half the battle in solving problems is being able to recreate them or observe them when happening. You might have great data that would help the developers.
