Hyoyeon appears on MMTG for SNSD's 14th anniversary. the episode has quite a lot of cuts and I'm surprised they didn't release it in 2 parts like for Tiffany and Taeyeon.
Hyoyeon promotes her upcoming single, "Second" without knowing when it'll be released and without teasers at that time.
full episode can be found here
sources: 문명특급 - MMTG, SM C&C STUDIO, 텔미썸씽_MZU Studio, @HYOVideos