There are 3-types of front/rear valences on the US-spec Mazda6:
1. Regular non-sport valence
This is a one-piece valence that is standard on i and s trims
2. Sport valence
This is a one piece sporty valence available only with Sport package and Value Sport package
3. Regular non-sport valence + front/rear lips
This valence is the same as the regular non-sport valence, but in addition, there are body coloured lips at the bottom of the front and rear valences. This makes it look similar to the Sport valence (# 2 above), but is two-pieces instead of one (and therefore has a visible parting line/crease). This valence is available with the Appearance package, or also available as asseccories for those with the regular non-sport valence (#1).
From your description, I think the loaner you have now has the Appearance package, and the one you ordered has Value Sport.