well, I think there's value to the picture the day off if we stretch the analysis by a lot.
On Dec. 18 the picture was of Toad about to get shot in the face by an arrow, probably symbolizing the idea that his chances were about to be shot to heck. By a Mario newcomer, Rosalina.
On Feb. 13 (14?) we got the picture of Peach with a rainbow. Captain Rainbow is one of the main reasons people in Japan are aware of Little Mac, who was revealed that day!
So yea, loose associations!
Also, right now I'd really really love to see Sakurai convince every major Nintendo/Smash-affiliated developer (Platinum, Retro, Level 5, Monolith, Intelligent Systems, Bandai Namco, etc.) to tweet/retweet about the direct so that we're all running around confused like headless chickens without knowing who to expect.