New-to-me methods... "decorating" mRNA with fluorescence!

I was reading a paper about ER targeting and mRnA and came across this interesting phrase describing a mRNA-fluorophore in a figure, "HAC1U1A mRNA decorated with U1A-GFP."

Which, naturally, immediately brought this to mind:

 But as we all know regarding microscopes, NO GLITTER ANYWHERE EVER!!!111!!

But as we all know regarding microscopes, NO GLITTER ANYWHERE EVER!!!111!!

I was genuinely interested in the method they were using to generate their mRNA-flurophore constructs, but I guess it will have to remain a mystery. A glittery, sparkly, mystery.