When Christina Aguilera turned up at the Season 4 premiere of 'The Voice' earlier this week (even though she sat out this season to work on her own slumping career), everyone was gushing about her weight loss and how terrific she looked.

She definitely looked great. But was it the result of a dramatic slim-down ... or is she just wearing clothes that fit now?

For reference, here's a side-by-side shot of Xtina on Wednesday, March 20, and in September 2012.

Kevin Winter (2), Getty Images

On the left, she looks taut and toned in a figure-appropriate Parker LBD, cinched with a studded Versace belt, nipping her at the waist and calling some attention to her below the neck assets, while taking some away from her badonkadonk.

On the right, she's a sausage about to burst its casing in a too-tight, too-clingy, too-unforgiving black frock. She's also slathered with too much makeup, aging her.

And while Xtina's arms look more toned, it's not like she went down three or four dresses sizes. She's still got enviable, to-die-for curves, but it shows that clothing fit makes all the difference when you're an hourglass. Wearing a fun, flirty frock like the one she chose for the premiere was a smart choice.

Kevin Winter, Getty Images

Even her legs are in terrific shape, lengthened by her black patent leather Christian Louboutins.

Kevin Winter, Getty Images

While Xtina has been known for her retro glam, crimson red lips and white blonde hair, the messy Cali-girl waves, mega lashes and nude lips are a reminder that less is more. She looks stunning, and the toned-down makeup easily takes 10 years off her face.

Again, here she is earlier this week on the left -- and in November of last year on the right.

Kevin Winter / Frederick M. Brown, Getty Images