A boy in a green shirt on a skateboard on a stone wall with graffiti
A long-haired boy riding his skateboard at a fast pace over a stone wall with graffiti.
Not all boys are long-haired. A skateboard does not always move fast.
A boy does not have to be long-haired.  The boy does not have to be riding at a fast pace.  Over is not the same as on.
The boy must not be long-haired and must not be on a skateboard at a fast pace.