If you choose to disobey this sign and walk on the rocks anyway, you can’t say you weren’t warned! This is a pretty clever sign. We can imagine this isn’t their first time dealing with warning signs. They know that if they’d just written “do not walk on rocks,” people would be tempted to do the opposite and walk on the rocks.
However, something that everyone can relate to is the risk of losing a law suit. People might take their chances with the slipping and falling on the rocks, but they wouldn’t take their chances with a law suit. That’s one clever sign in front of you, although those rocks look very climbable!