How Does Lux's Q (Light Binding) Work In Lore?

Just something that's been bothering me for a while. The rest of her spells make some canonical sense; her W distorts the light around whoever she's shielding to make it harder for enemies to hit them accurately, essentially giving them a shield. Her E distorts light to confuse and slow people, possibly slowing their metabolism, before exploding. Her R is literally just a laser (you can even see the heat distortion after it's been used). But how does her Q, which prevents people from moving entirely, make sense in lore?

I remember pre-retcon that Lux's Q was the result of her reverse-engineering Morgana's Q, because Morgana was allied with Noxus at that time. With the retcon though there's no reason to believe that Morgana and Lux even know each other exist.