Casually dressed young males and females are sitting and laying on a grassy area with bicycles and other personal belongings reading on a sunny day.
A bunch of people are hanging out in the park in the middle of classes.
You can not infer they are in the middle of classes.
The place may not be a park and the people are not in the middle of classes
Being in a grassy area does not mean they are in the park.  Reading on a sunny day does not imply they are doing so in the middle of classes.