Quick aside: while I'm not usually that keen on finding meaning in every little oddball thing, it's difficult for me to see the bit with the fish as anything but a shout-out to Sam Keith's The Maxx. Here's a sample from one of The Maxx's hallucinations: "That fish is your conscience, and she's wheezed her last wheeze! You're all alone, Maxx...your misson's forgot. The only one who can remember is Snot. Your face is a figment of a man with no head! Your mask, it is evil and your fish...it is dead!" And it's a goldfish in a little glass bowl, too. I probably didn't need to quote all of that, but I hate to ruin the rhyme scheme.
Anyway. Fred turns back to Angel and sadly reports that she can't find anything wrong with him. She peers down into the cavity in his chest and sighs, "You're empty. There's nothing left. Just a shell." She leans down over him and says she thinks she can hear the ocean. Heh. Then we cut to a, uh, intestine's-eye-view? Well, a shot of Fred from inside Angel. She says "Hello?" and we pull back, or sink, until the screen is black except for the tiny image of Fred's face at the distant opening. And then we pull back even further, and it's a close-up of Angel's pupil. Ooo, fancy. Angel twitches and mutters restlessly in bed.