The 'Who's That Wonderful Girl' meme originates from the Canadian children's television series Nanalan', specifically an episode where the main character, Mona, dresses up as a princess. Her grandmother sings an endearing song while Mona dances in a cardboard castle. While the show originally aired in the early 2000s, it found a massive resurgence on platforms like TikTok and Instagram in the 2020s. Users utilize the audio and visuals to celebrate self-love, show off adorable pets, or highlight characters that embody a 'precious' aesthetic. It has evolved from a nostalgic childhood clip into a universal internet symbol for wholesome vanity and pure joy.