It's supposed to have a "sheer veil of colour" that "blends effortlessly," but it is still labeled as a "highlighter." Most, if not at all (depending on the shade, of the shimmer is an overspray (as is the gradient effect), and this is in line with this formula -- MAC's "High-Light Powder" has typically been over-designed with a more underwhelming product underneath. It's one of the most confusing formulas MAC has in their arsenal, because it really doesn't jive with the expectations they set with the overspray nor the product's name. It's too bad they didn't pull out their Blush Ombre formula from years past.
It's just not at all what anyone would expect with a formula name of "High-Light Powder" nor with how it appears in the pan (upon purchase). Most of the iterations I've come across are more blush-like in color with semi-matte to matte finishes that really mattify the skin rather than bring in any luminosity. The colors have ranged from pale pink to brown to coral. Even Marine Life was nowhere near a highlighter, which I recall being one of the more covetable MAC products of years gone by.
The average rating based on all reviewed shade(s) in this formula is shown below.