This is probably the first time I've seen a manga outright say lesbianism is different from yuri.
Yuri ≠ lesbianism is so wild
It's true though. Most yuri is as described, blushy wushy highscool girls (or younger) going "U-uwaaah b-b-but we're both girls Machi-senpaaai! Uwaah my heart is going doki doki at the touch of your hands in mine!"
Nothing like actual lesbians, the lesbian experience and being a lesbian which many g.i.r.l.s (guys in real life, whom of which are usually men named Alice or Lilith with CS degress) like to think it is.