Probably the easiest thing about this comparison is that the 2 polishes, China Glaze - Luxe and Lush and OPI - I Lily Love You aren't too similar. But they are definitely in the same nail polish boat, both having flakies within.
China Glaze - Luxe and Lush has a clear base with blue/yellow toned (depending on the light) flakies. I personally think it looks best on a blue manicure. I don't know how to describe the flakies as in it's type (eg iridescent, holographic etc.), I'm positive someone else will have described it far better.
OPI - I Lily Love You has a sheer pink base with iridescent glitter of different shapes (squares, triangles) and flakies. I feel like this can also enhance different colour with the sheer pink base.
I'll let the pictures do the talking.
I much prefer I Lily Love You, it's the iridescent glitter and the pink base, it's so pretty. I like Luxe and Lush but I used to like it more. Both hands have 2 coats of the respective glitter.