Mrs. Bieber just posted several professional shots of her wearing her custom backless gown, which was commissioned by Louis Vuitton's artistic director for menswear, Virgil Abloh. Sounds like he had it done through his other fashion company though ... Off-White.

Hailey thanked Virgil and co., writing ... "@virgilabloh thank you for making my vision come to life and creating my dream dress. You and your @off____white team are incredible and I’m forever grateful I got to wear your beautiful creation ❤️."

She also threw in some pics of her and the groom together, with Justin looking super spiffy in his tux. Hailey captioned a photo of them with, "last Monday was the most special day of my life:)." The words "TILL DEATH DO US PART" were embroidered on her train too.

Hailey threw in some extra photos for good measure -- another one of her and JB kissing, but close-up this time. She even added a shot of their bling ... AKA, their rings.

Still no photos of them at the altar down in South Carolina though ... looks like we'll have to wait on those.

Here's what we do know though -- Hailey changed at least once during her and Justin's wedding reception ... and now, we know THAT dress was preceded by something even more stunning. Seriously, she looks absolutely angelic here -- imagine her in real life!!!