Doesn't mean anything. Shinbou Akiyuki has always (well, since Moon Phase and PPD) inserted completely random references to things in his anime. Yukkuri Reimu just seems to be his latest favourite thing to reference. It had quite a presence in that OVA and made an appearance in Natsu no Arashi (also directed by Shinbou) as well. I'm sure we'll encounter it again in Zan Sayonara Zetsubou Sensei.