Master finds the slave napping during the day, so He decides to tie him up and use his face as a footrest. The slave must lick every part of Master's sneakers, including the soles, while the Master is laughing at him and humiliating him verbally. He won't stop until His sneakers are shiny clean and the slave's face is tired from the pressure of Master's feet.
Two angles - full view and a close-up of sneaker licking.