The glitches and RNG exploits are still rampant in Pokémon Brilliant Diamond & Shining Pearl. RNG exploits are nothing new to the franchise but this particular exploit found by Papa Jefé (what a name!) is interesting as it involves watching character blinks in before the game even starts. The prize for your patience is a guaranteed shiny starter.
If you’re interested in trying this complex method, check out the video’s description for a bunch of links and tutorials that can help.