The Essentia Funnel is a block added by Thaumic Tinkerer. It needs to be on top of a hopper that is on top of a Warded Jar in order to function. If a Warded Jar that is on top of the funnel contains the same aspect as the one that the hopper is pointing at (or if it is empty), it will transfer the essentia from the top Jar into the bottom Jar.
You grew tired of managing your jars with phials, to that, you created this new mechanism to transfer the contents of one into another.
By placing this block above a hopper, and right clicking it with a filled jar, if the hopper is pointing into a jar that's either empty or of the same aspect, the contents of the jar will be transferred over.