tataḥ kṣīyate prakāśa-āvaraṇam
Then the veil [surrounding your light] disappears
Here, Patanjali reaffirms the source of pure light within us all. Prāṇāyāma is a process of purification, and its practice allows the pure light within you to radiate from you. When you are the best version of yourself, other may also bathe in your light.
For a detailed guide on the practice of prāṇāyāma see: So what is pranayama? (pranavashyauk.com)
Damian Cadman-Jones is an authorised teacher of Prana Vashya Yoga™