"Mirror Mirror" is episode 11 of the Trollz television series.
"To avoid ridicule from friends, Sapphire returns her new pair of shoes only to purchase another fashion emergency, a magic mirror pendant. When the magic mirror flatters Sapphire's ballooning ego, her head gets stuck in the clouds and she accidentally opens a magic portal! The friendly face from the mirror was Simon! Only the magic of the five can bring Sapphire back down to earth - pun intended."
Sapphire buys a pair of blue shoes for Jasper's upcoming party, but her fashion choice is questionable, and a miscast spell that makes her smelly feet glow leads to teasing from her friends. When she goes to return the shoes, she finds a magic mirror pendant that speaks to her. The voice flatters her and tells her that she's special, leading her to ignore her friends even when their concerns are legitimate, blame them for a run-in with head cheerleader Coral, who bullies her when she finds out that her feet smell, and grow condescending and power-hungry to fellow students and teachers.
Later that night, the mirror tells Sapphire that she's so special that only she can cast a powerful spell to free him from his prison. The other girls go to check on her just in time to see her cast the spell, and the mirror turns out to be Simon! Free from his banishment in the Shadow World, and with Snarf and an army of orcs at his side, he plans to invade Trollzopolis, but not before his orcs eat Sapphire. The others enter the portal and rescue Sapphire, who finds that her light-up cheesy feet turned out to come in handy—the orcs can't stand bright lights. Working together, they drive Simon off, and afterwards apologize to Sapphire, who apologizes to them in return—though Ruby can't resist one last joke about "Twinkletoes."
Sapphire has smelly feet - when she takes her shoes and socks off in school to show her friends her glowing feet, cheerleader Coral can smell them from down the corridor, and teases Sapphire. Later, when she removes her footwear to fight off the orcs, Onyx makes a comment about her foot odor scaring them off (though in truth they weren't scared off because her feet stink, but because of the bright light each time they flashed).