You is nah no "convert" to rastafari"anism", you is Rastafari.
If you check that hand gesture, it is also the star of david, which is like 'as above so below' cos its two triangles (pyramids), one on the earth reaching up to the sky, one in the sky reaching up to the earth. Also if you notice, when your fingers are in that position you can feel your heartbeat strongly in them. This effect is magnified when the herb is moving through you.
Well that is just my personal observations of that hand position.