The blessings of Maa Baglamukhi develop a divine protecting protect in the form of an aura about someone thus defending him/her from malefic energies in the form of black magic spells or evil eye. A different etymology suggests that valga implies "to paralyze" and symbolizes the strength of stambhana, "paralysis" https://www.youtube.com/shorts/5VeSyP9JRw0