mission reward items for vette: slicing armored or civilian?
Humanoid Companions use the look of their equipped gear, just like player characters.
The quest is simply offering a different set of (as you noticed) identical armor, so that your Vette can have some variety from the other 30 Vettes currently running around Korriban.
Here's picture comparisons (found via ToRHead):
Slicing on left, Civilian Outfit is on the Right.
Armored is here (don't want to spam images...)