Christina Aguilera is still going strong.

The singer, who celebrated her 44th birthday on December 18, celebrated the occasion in grand style, sharing a truly stunning photo on Instagram.

In the black-and-white photo, taken by photographer Etienne Ortega, the star poses topless, crouched down, and stares sullenly at the camera. She is wearing a baker boy hat, which was famous for rocking in the 2000s, with matching leather booty shorts and strappy heeled sandals. Her hair is styled into bleach-blonde ringlets, like Marilyn Monroe and Madonna in the 1980s.

“And she Keeps getting Better,” Ortega commented. [Meanwhile, Claudia Norvina Soare, president of Anastasia Beverly Hills, said, “Queen! Happy Birthday."

Hollywood's ‘Eyebrow King’ Damon Roberts said, ”This is what it means to be old but look young!!!” he added.

People noted that the look is reminiscent of Aguilera's style in the 2010 film “Burlesque.”

Most recently, Aguilera made headlines for her guest appearance at Sabrina Carpenter's Short and Sweet Tour show in November.

She posted a video of that concert on Instagram after the fact,

with the caption “Thank you @sabrinacarpenter for welcoming me into your world.” TV personality Marvyn commented, “MOTHER IN HER MOTHERING ERAA,” while the official Bratz dolls account added, “This is what heaven looks like”

. And last year, the singer very kindly shared all her favorite beauty tips and tricks with Marie Claire.

In particular, she shared who she considers her beauty icon: “You can't beat classic Marilyn Monroe. I can't compete with the classic Marilyn Monroe. But I love creative people. My ultimate icons are Cher and Madonna. I like veterans, people who have been through a lot of experimentation.