Board Thread:General Discussion/@comment-26006155-20190131130037/@comment-38339538-20190131205020

The reflection of Chara in the puddles only happens in debug mode, which is the version of the game Toby Fox used to test the game for glitches. It was never meant to to be seen by fans and is only accessible by editing the hex codes of the games data.win file. The inclusion of the Chara's reflection in debug mode marks it as unused content that didn't make it into the final game, and is therefore not plot relevant, otherwise it wouldn't have been scrapped.