These two men are Manusmriti Das. Manumission is the act of a slave owner freeing his slaves. He just borrowed clothes and hats for the picture. This is a drawn-out picture and a statement about estrangement rather than a picture of a woman with her slaves.
To answer the question of why they are dressed but bold - this is part of the old custom of using shoes to denote class, status or wealth. It was highly customary that slaves were kept barefoot. Some countries have even said that slaves always live without shoes.
The motives of slave owners in enslaving slaves were complex and varied. First, manumission can present itself as a sentimental and benevolent gesture.
A typical scenario was for a dedicated servant to be released from the master's will after long years of service. This type of manusmriti was generally confined to slaves, who maintained some degree of closeness with their masters, such as those serving as personal attendants, domestic servants, secretaries, and the like.
In some cases, there was a prolonged sexual relationship between the master and the slave. The owners sometimes freed the woman and children born from such relationships.