All right, @zpaolo11x, I took your code and wrapped it in a class (attached). It works for me...the typical way it should, I think, but in the grander scheme of things, it doesn't work for my purposes! I think it has to do with how the first image (a video in my case) doesn't come up on layout start: you have to navigate through the list to trigger things. I think if I can solve this issue (which I still have no idea how to do!), I'd be good to go.
For those with less ridiculous layouts than me, here's how to instantiate the wrapped drop-shadow (there's better "documentation" in the .nut):
fe.do_nut( "drop-shadow.nut" );
local myPic = fe.add_artwork( "snap", 100, 100 ); // Arbitrary placement
local myPicDS = DropShadow( myPic, 25, 0, 10, 153 ); // Shadowed object, blur size, x-offset, y-offset, alpha (0~255)
You'll need zpaolo11x's gauss_kernsigma_o.glsl file for any of this to work!
If anyone has any idea why my layout isn't showing a snap when it first loads, I'm all ears! Thanks!