Two girls playing catch on a lawn
Sisters are tossing a frisbee back and forth in the park.
Two girls playing catch on a lawn does not mean they are using a frisbee for that game, or that the lawn is part of a park.
Not all girls are sisters.  Playing catch does not imply that they are playing with a frisbee.  Being on a lawn does not imply that the lawn is in the park.
Just because two girls are playing catch on a lawn does not mean they are tossing a frisbee.