Although it is largely a posed photograph, there are components of spontaneity here. Prince William and his fiancée Kate Middleton are shown in an embrace - and the detail to notice is the amount of contact. William's arms and hands are in full contact, including palms - indicating significant and deep affection. When love wanes, there is less and less contact. Eventually the palms will rarely touch the other's body- just the finger tips will make contact. Not so here. Kate's palm on William's chest signifies "ownership" and passionate feelings as well.
On a slightly different note however, William needs to work on his smile. Remember - a true smile doesn't expose the lower teeth. The corners of his mouth of the Prince's mouth are pulled out to the sides instead of primarily upwards as Kate so nicely demonstrates. In his defense though, he has had to "smile on demand" his whole life and such exposure makes it tough to summon up a true, felt smile on command. His father, Prince Charles, also has this flaw to his "social smile".