Then why ask the question on an open forum to begin with? If you just wanted people to agree with you, shouldn't the thread have been "I'm going to give my free Diamond picture away, post here if you do the same".
To the topic of the thread, I think Merion Mom hit the nail on the head. It might work, it might not. I have given mine away in the past, but I've also been told no because I wasn't in them.
Just remember that you haven't earned any "rights". You've earned loyalty perks. Perks which can be taken away at their discretion if they feel it is being misused. It's great they allow us to share the unused drink vouchers, but they apparently haven't given that same blanket ruling to the photos. This isn't unkind, it's just reality.