According to this Wikia page, where it discusses the difference between TV and DVD:
One of the most notable differences is the change of Nanoha's infamous "dead" expression when casting Crossfire Shoot on Teana in StrikerS to a more disappointed one.
When I bought the DVD Set which had all 3 series and the 2 movies from eBay, I assumed it was the proper Japanese DVDs. However, given how often the subtitles change fonts and how the translation of the names and terminologies changes in later episodes, it's obvious the seller made the copies from fansubs.
That being said, I am unsure if the episode I saw were ones from the DVD release or the Japanese television release.
So I am wondering, what is Nanoha's "dead" expression? How does it compare to her disappointed one? And why would it be changed?