This is my opinion (and is probably wrong):
I think this song is about someone who has a great deal of pressure but on them to be the light (strobe light- get it?) for everyone and save them. And they have to appear all like glitter (like there's nothing wrong and they're perfect etc.) but inside they aren't like that and feel traumatic and stuff. And the person that makes them feel invinsable and makes them happy isn't there anymore so they're dreaming of that person singing that song to them or something.
This is my opinion (and is probably wrong): I think this song is about someone who has a great deal of pressure but on them to be the light (strobe light- get it?) for everyone and save them. And they have to appear all like glitter (like there's nothing wrong and they're perfect etc.) but inside they aren't like that and feel traumatic and stuff. And the person that makes them feel invinsable and makes them happy isn't there anymore so they're dreaming of that person singing that song to them or something.