What you are seeing are samples for wallpapers from Pokémon Card Game Online, a Japan only browser game that lasted 9 months from November 2009 to August 2010. Yes, those are gijinkas of the Gen 2 legendaries, they were assistants tied to the team of the player's allegiance.

>sauce
https://web.archive.org/web/20100918101642/http://www.pokemon-card-online.com/wallpaper/201008_wallpaper.html
>Leafeon vs Metagross Expert Deck +Online commercial
https://www.youtube.com/watch?v=lHyDk5b034A
>quite possibly the only playthrough footage of PCGO on the internet
https://www.nicovideo.jp/watch/sm8875178
https://www.nicovideo.jp/watch/sm9612799