D.Va is originally "Hana Song, 'pro' starcraft 2 player in the game's lore. Put into the mech when korea needs people to fight in them. She streams that while fighting on the battle field. Now the meme also generally is cause of the paint on her face resembling dorito's and her being a gamer girl drinking mountain dew.
1st video: she forgot they are cameras EVERYWHERE!
4th video: mercy-saurus rex
5th video: genji trolls, hanzo doesn't want to say noon, and zenyata is stumped by the recaptcha.
6th video: idiot doesn't realize he has a stalker