Call fingers angled like branches what peel and cut apples,
to give to a girl who eats them in silence, looking.

Call the things that peel and cut apples to give to a silent, looking girl "fingers"

Call her afterward tree, call her seawater angled by silence.

Call the girl "tree", also call her "seawater angled by silence"

-- and I think the last phrase may have a double meaning:

1. same as rest of poem, i.e. when I say "seawater angled by silence" I mean "the girl"

2. call up for the girl (order, conjure up, recall/recount to her) seawater angled by silence.

Forced to choose, I'd choose # 1

I'd been thinking of "angle" as in fishing, but it could be "angle" like "slant"