IMHO, the president accepted the request out of his kindness, probably thinking photo is only for the couple's personal keepsake, but ended up being part of the photographer's social media trip. Which is not unexpected, people had been pasting pics of politicians here and there, from photographer sites to hawker center stalls.
Side track a bit. He became a patient of mine once, back in 2008. Very nice fella. He insisted in not jumping queue. Waited and sat among the ordinary people.
On a separate account, the other One (I won't mention his name) is the exact opposite. Complained and grumbled even though He ordered for total exclusivity of our whole department. Scold here and there. First time I handled Him and I have to admit I got rattled good.