Continuing with the same theme I mentioned above, Yosef wanted to make the brothers feel appreciated by their father. How?
When Yosef went missing, Yaakov became inconsolable. Perhaps the brothers thought that Yaakov only felt that way when Yosef was missing, but Yaakov would not miss them. Yosef imprisoned Shimon and sent them home in order for them to see Yaakov’s reaction – that he grived for Shimon also. Remember that Shimon was rambunctious and caused trouble in Shechem. Even so, Yaakov still grieved his absence. The Shevatim now learned how much their father cared for all of them.