Here's what happens:
* In the 2003 anime, Edward walks in on Winry as she's changing in a very brief scene. This happens during a comedic moment where Edward is trying to find a missing piece of his automail and stumbles upon Winry changing. It's meant to be a funny and lighthearted situation, not a serious or inappropriate one.
* In the 2009 anime (Brotherhood), this scene is not present. While there are moments where Edward and Winry are in close proximity, there's no instance of him directly seeing her change.
It's important to remember that both *Fullmetal Alchemist* and *Fullmetal Alchemist: Brotherhood* are shonen anime, and their focus is on action and adventure. While there are romantic subplots, the series avoids overt sexual content. The scene in the 2003 anime is a comedic moment that was likely intended to be funny rather than explicit.