In one of the short videos (in one of the Daily Mail articles) one can watch as the Queen and Sophie both let their gaze drift sideways to take in Prince Philip who seems to be struggling to maintain an upright balance (the video cuts off at a crucial moment). It's obvious to me that he is seriously impacted. The Queen's tears may have had many reasons, in fact.
A very poignant moment for many, many reasons.
BTW sitting and standing are two different capacities (from a certain perspective). Sitting in a cart one drives could still be done, while prolonged standing is an effort. Both can exist side-by-side. Anyway, very gallant, and dedicated, for him to have made the effort. The Queen, too, seemed fragile on her feet. Time is passing.