ITZY's Chaeryeong revealed that she practiced smiling by watching performances of Red Velvet's Joy. 

On the August 6th episode of JTBC's 'Knowing Brothers', ITZY members appeared as guests. When Heechul asked ITZY about the hardest part of promoting their latest song "Sneakers", Chaeryeong answered practicing smiling was the hardest part. 

Chaeryeong added, "Before we could let out our emotions along with the tough choreography thanks to the songs' charismatic concepts but now we have to keep our smile despite intense movements." 

Kang Ho Dong asked if she took lessons on how to keep smiling, Chaeryeong said she watched many videos of her seniors. She commented, "I referred to Red Velvet's Joy a lot because she has the most beautiful and natural smile."