Unlike most of her pop-star peers, Billie Eilish is known for covering herself in oversize T-shirts and baggy jeans.

That’s why fans were stunned to see the typically modest five-time Grammy-winning 18-year-old peeling off her shirt during a concert Monday night at AmericanAirlines Arena in Miami.

The “Bad Guy” singer-songwriter broadcast a big-screen video in which she stripped down to her bra, apparently making a bold statement about the pressures young women face in the music industry — and the online body shaming that comes with it.

Her moody monologue played out over an ambient instrumental track, with Eilish dressed in her signature slouchy style before stripping down.

Fan footage posted to Twitter features Eilish intoning, “If I wear what is comfortable, I am not a woman. If I shed the layers, I’m a slut. Though you’ve never seen my body, you still judge it and judge me for it. Why? We make assumptions about people based on their size. We decide who they are, we decide what they’re worth. If I wear more, if I wear less, who decides what that makes me? What that means? Is my value based only on your perception? Or is your opinion of me not my responsibility?”

By the end of the clip, the “No Time to Die” singer is pictured peeling off a form-fitting black tank top, exposing her black bra and long, jet-black fingernails.

One freaked fan can be heard screaming, “What the f–k?! No f—ing way!” as the crowd roared in response to the revealing moment.

Eilish has been outspoken about feeling “very hated” by the public amid her massive newfound success, but it appeared Monday that she’s upbeat about regaining control of her image despite critiques from online trolls.

At one point during the concert, the Miami New Times reports, the singer announced: “I need water.” After taking a swig, she playfully squirted the rest of the bottle all over her overheated fans.

The full text of Eilish’s spoken word performance follows:

“You have opinions — about my opinions, about my music, about my clothes, about my body.

Some people hate what I wear, some people praise it, some people use it to shame others, some people use it to shame me, but I feel you watching — always — and nothing I do goes unseen.

So while I feel your stares, your disapproval or your sigh of relief, if I lived by them, I’d never be able to move.

Would you like me to be smaller?

Weaker?

Softer?

Taller?

Would you like me to be quiet?

Do my shoulders provoke you?

Does my chest?

Am I my stomach?

My hips?

The body I was born with, is it not what you wanted?

If I wear what is comfortable, I am not a woman. If I shed the layers, I’m a slut.

Though you’ve never seen my body, you still judge it and judge me for it.

Why?

We make assumptions about people based on their size.

We decide who they are, we decide what they’re worth. If I wear more, if I wear less, who decides what that makes me? What that means?

Is my value based only on your perception?

Or is your opinion of me not my responsibility?”