Crucifixes in which Christ is Pointing

We’re not aware of any significance regarding the left hand. We infer that what you’re seeing is what non-crucifixion images of Jesus Christ often portray and usually with the right hand. The pointing of the index and middle finger upward signifies the two natures of Christ, that he is both human and divine. If the thumb is also upraised, this signifies the Holy Trinity. If just the index finger, that would signify there is one God.