The blessings of Maa Baglamukhi create a divine protective defend in the shape of an aura around somebody therefore shielding him/her from malefic energies in the form of black magic spells or evil eye. One more etymology suggests that valga implies "to paralyze" and symbolizes the strength of stambhana, "paralysis" https://www.youtube.com/shorts/5VeSyP9JRw0