Why would the slavers feed and clean the slaves before the slaves were put on an auction block?

Feeding and cleaning the slaves before an auction could increase their value and appearance, leading to potentially higher prices. Slavers might have done this to present the slaves in a better light to potential buyers and to generate more interest in their sale. Additionally, it could create the impression that the slaves were well-treated and cared for, potentially attracting buyers looking for healthier and more presentable enslaved individuals.