In the manga, Izumi sent her employee, Mason, to the island with the Elrics as a masked figure who terrorized them but ultimately watched over them. This is left out of the anime.
Izumi's scene from the manga where she explains the concept of death to a little girl, via the child's dead cat, is also omitted.
Bait-and-Switch: Ed and Al have, several times in the past, mentioned their "scary teacher" who taught them alchemy. So when we first meet Sig Curtis, who is rather frightening in appearance and is introduced carrying a butcher's axe, it's easy to assume that he is said scary teacher. However, despite having a Face of a Thug, he's actually quite a nice man, and his hot-tempered wife Izumi, who is introduced soon after, is their real teacher.
Eyecatch: Both Curtises (Izumi and Sig) for both of them.
Face of a Thug: Sig Curtis, who is rather terrifying-looking, but is ultimately a nice and mild-mannered man. (His wife is the one with the violent temper.)
Figure It Out Yourself: Izumi gives Ed and Al a month to figure out the meaning of "All is One, One is All", as a test to decide whether or not she will take them on as her students.
Sink or Swim Mentor: Izumi's approach, especially in her first lesson for the Elrics.
Stepford Smiler: After she explains to Ed and Al her encounter with The Truth, she asks them if they suffered from their incident. They immediately put on brave faces, as if it’s not a big deal. Izumi responds by embracing both of them, assuring them that they don't have to act so strong all the time, which causes them to break down and ask for their forgiveness.
Stern Teacher: Izumi, very much so. To the point that the Elrics are absolutely terrified of her.
Whole Episode Flashback: Much of this episode is a flashback to the Elric brothers' tutelage under Izumi.
