It is a court of arbitration, it has no power to enforce its decision. Philippines can go to war, impose sanctions or get a UN Security Council resolution against China, but none of these will happen. Philippines will not go to war with China clearly. It is also too small economically to impose sanctions against China. China has veto power in UN Security Council, Philippines will never get a resolution from UN Security Council without China vetoing it. All Philippines can do is make some noise in the media which China doesn't care.
In another word, this is just a drama in the international theater concerning South China Sea involving actors such as US, EU, China and Philippines. It will have no real life consequences.
One thing that is also noteworthy is China has never agreed to the arbitration. An arbitration needs two parties to agree to the arbitration to work. Philippines submitted the case unilaterally. The Permanent Court of Arbitration should not have accepted a case submitted unilaterally by one party. The Permanent Court of Arbitration has shown itself to be a political institution and not a judicial institution in this instance.
This has damaged the reputation of the Permanent Court of Arbitration. Is this surprising? Probably not given the influence of the West on the Permanent Court of Arbitration. However, the rest of the world will see the Permanent Court of Arbitration as political and will set up its own court of arbitration that is apolitical.