The Blessings of Maa Baglamukhi develop a divine protective defend in the shape of an aura all-around someone thus preserving him/her from malefic energies in the shape of black magic spells or evil eye. One more etymology suggests that valga indicates "to paralyze" and symbolizes the power of stambhana, "paralysis" https://www.youtube.com/shorts/5VeSyP9JRw0