The 140mm figure (which is in scale with the Rider and Sentai figures that S.H. Figuarts also produces) includes three different heads (for different facial expressions), three different left hands, five different right hands with two Moon Sticks (one with the Ginzuishou in the slot and one without), an in-scale Luna companion figure, and a Moon Tiara effect. If this is similar to other superhero figures, it will most likely be a translucent aura effect to simulate Sailor Moon's famous Moon Tiara Action finishing move. The brooch will be the classic first series brooch.
Expect the level of articulation consistent with other S.H. Figuarts figures, and if you purchase in the first run, you'll probably get the special first run item as well; in many cases, this is a plastic stage designed specifically for the figure, such as the ones that came with the first-run Akiba Red last year.
I clearly need her, since she clearly needs to be best friends for life with Kamen Rider Fourze and Akiba Red. The manufacturer's suggested retail price is 4,410 yen, but the price usually goes down fairly soon after release.