What am I doing wrong?

Today, I started polishing back some lips. I stripped the clearcoat first (flapper wheel + nylon brush), then proceeded onto wet-sanding with 240/400/600/800/1000/1500/2000. I spent the most time at 240 grit sanding back some of the scratches made by the flapper wheel and nylon brush, and I made sure no deep scratches got past that stage. Onto the polishing stage, I started with black compound on a sisal mop, used detergent + warm water as instructions to get rid of burn marks and other residue, then white compound on a soft mop, followed by hand polishing using Mothers Mag/Alu Polish. Here were the results:







Disregard the area where the bolt inserts are, I deliberately didn't spend as much time on them as the bits we can actually see. What I'm annoyed about is why there's still some fine lines (camera couldn't capture them but they're there, running perpendicular to the outline of the lip) and the presence of those water mark-like marks... I went over the lip with liquid polish by hand but they're still there... What did I do wrong?