Juliane looks young and the title identifies her as being from Braunschweig-Wolfenbüttel so this may be an advertising portrait from before her 1752 marriage or painted to commemorate her marriage.
From Wikimedia.
Juliane Marie is theatrically dressed in tight sleeves and buttoned split bodice over a chemise. She is lavishly arrayed in diamonds, often tremblant. The jeweled clasps of her split bodice continue a line beginning at her order bow and bodice jewel.
Keywords: Queen Juliane Marie of Denmark, Juliane Marie von Braunschweig-Wolfenbüttel-Bevern, Juliane Marie af Braunschweig-Wolfenbüttel-Bevern, dronning af Danmark og Norge, Duchess, Queen, Oldenburg family, curly coiffure, jeweled headdress, chemise, lace modesty piece, scoop neckline, split bodice, vee décolletage, lace bertha, three quarter length tight sleeves, lace engageantes, vee waistline, full skirt, girandole earrings, order bows, jeweled bodice ornament, wrap, regalia