The young man in the plaid shirt is sitting on a chair that is out in the yard.
A boy is watching a cartoon from a recliner.
Recliners are typically not the type of chair that is kept in the yard.
Young man could refer to youth or a teenager and not just a boy. Makes no sense for someone to be sitting on a chair and watching cartoon out in the yard.
If the young man is in the yard, the young man is outside.