In most people this charisma is due to the vital constitution, especially an expansive vital. It is not necessarily a good thing from the higher spiritual perspective, especially of personal growth. Though some put their vital charm to good use by drawing people and forces towards them which can be then offered for Divine Purposes. But this is rare. Most often it simply acts as a force of vital attraction that only makes one more and more self centered and live in grandiose imagination.
However there is something called as spiritual charm and emanates from a childlike inner state of divine simplicity and sweetness flowing out of the soul of love, bhakti for the Divine and a life consecrated to the Divine.
Affectionately,
Alok Da