Shower head leaking leaking after shut off?

Under pressure water still in the pipe line... Normal - water will drop down out of that pipe until it runs dry. You could put a value shut on it. But the water will just end-up being in the pipe until next time. Still it should stop after a few minutes. Do you have a rain shower head? Those store a lot of water in there. I had one drip, drip until it was empty.