That would most likely be because a Female Pikachu has a difference in the tail, whereas there is no barely any noticeable difference between the Raichu genders.
Either that or, I dunno.
I've heard people think the Scyther sprite was butchered, but I honestly like it. It has more of an edge to it now, and just seems more like a stance something that was alive might take.
You know, while some people say that some sprites went back a step, I believe that that was the point here. I like the sprites because they are a mix between the gsc and platinum sprites. These are like redrawn johto sprites from the gbc.
Serebii now has the pre battle pics (like of Gym Leaders).
One of them looks like the mysterious sprite that people think is Giovanni. I have a question. What does the fake director in Goldenrod look like when you battle him?
Does he look like a Rocket exec? Ie., his battle sprite.
At first I thought the sprites were really bad, and poorly done by an average spriter. Though now that I look at them more, and get used to them, they are pretty good and badass.
I can also sense the G/S-esque feel in the sprites. Amazing =D
I personally dislike most of the sprites. Jolteon is in its worst condition since Red/Blue and Mewtwo is completely lulz-worthy. Umbreon still isn't up to snuff, but it looks a lot better than it did in DPPt. Tyranitar...looks like it's sad and it wants to cry and Sneasel is...just bad.
However, Arcanine, Steelix, and the legendary dogs are amazing.