This is kind sad. Although they are all happy, based off of the people in the background, this was before Calamity Ganon. This is probably their last happy moment together before 4 of them die, one is horribly wounded, and the last one is used in a spell to keep Ganon at bay. And they don’t even know. They do, but it is so far back in their minds during all of their happiness. Just saying.