As a depiction of labour, this picture is greatly idealised. The workers are spotlessly clean despite their drudgery. The church in the distance, and the farm manager on the horse to the right, serve as reminders of spiritual and social authority.
Stubbs’s picture can be seen as a celebration of the order and nobility of rural life, in tune with the concern with efficiency shown by agricultural writers of the time like Arthur Young. Alternatively, you may think that his picture robs these workers of their individuality and denies the harsh realities of work for sentimental effect.