How does the plugin work?

If in the dispenser (yes, the dispenser and not in the ejector, it is logical that in the ejector, but the dispenser is more expensive, so I do not know ..) there is an empty bucket and there is a cow in front of it, aimed at its hole, within a radius of 1 block, then Mr. dispenser, instead of throwing away the bucket, gives the cow to the last drop.