Late May 2011 state dinner in UK.
The person may be Mark Brezinski who began serving as Ambassador to Sweden Nov 2011.
But did not see other pics placing him at the state dinner.
He replaced Matthew Barzun as Ambassador to Sweden (Aug 09- May 2011). Barzun then became Ambassador to UK (Dec '13-Jan '17).
Based on the room and Queen's outfit, this may have been the lunch at Winifred House.
The state dinner including clebrities was a more formal affair. CBS article does not Hanks as a guest. For the Winifred lunch, still going with Brezinski (9yrs younger than Hanks, so 45 in 2011)
https://www.cbsnews.com/news/obamas-join-royalty-stars-at-queens-state-dinner/
Thinking Mathew Brzezinski who was preparing to take over as Ambassador to Sweden, 45yr in 2011.
May 2011 state visit with lunch at Winifred House, less formal. The big formal state dinner included celebrities, 171 guests, including Hanks, who would be 55 in 2011.
Hope somebody on Q Team sees your post Anon
and suggest to the State Department to move the tail from center to right
that would be a Q Proof