The vivid colors prompted me to look up Mair von Landshut to verify he was active at the time rather than being active in the 20th or 21st centuries.
From jeannedepompadour.blogspot.com/2013/04/german-style-from-1468-1588.html. Also posted to the Early 1500s - 1470 to 1550 here.
Jadwiga appears to be wearing a low-cut dress that emphasizes her figure in this portrait.
Keywords: 1502, von Landshut, Jadwiga Jagiellonka, Hedwig Jagiellonica, Markgräfin von Brandenburg, Jagiellonowie family, Hohenzollern family, Princess, Countess, hair jewelry, jeweled brim hat, choker necklace, necklace, jeweled off shoulder scoop décolletage, jeweled fitted bodice, jeweled quarter length tight upper sleeves, arm bands, long full tapered virago sleeves, bracelets, flared cuffs, waist band, natural waistline, close skirt