"Excuse me, sir, would you mind taking our photo?" →
Steve paused for a moment as an iPhone was extended to him, realizing that they didn’t seem to know who he was. With a hint of enthusiasm, he said “Sure!” as he took the iPhone into his hands.
Steve took a great deal of care composing the photo, backing up a few steps several times, tapping the iPhone screen to lock focus, then said “Smile!” as he snapped the photo, grinning a little bit himself to encourage the family to follow suit.