interesting photo...
i don't know the answer to your question...
all i can say is that i feel relaxed just watching these water-scooping and water-dropping mechanisms.
I know at some of the temples it's to "purify" yourself before you go in. People rinse off their hands, sometimes their feet. You might even see someone rinsing out their mouth. Without seeing a wider shot it's hard to say if that's what this fountain is for.