As we discussed in the "Form and Meter" section, "Lady Lazarus" is a pretty intense sounding poem. While it doesn't have a set rhyme or metrical scheme, there are tons of repeated sounds (like rhymes) all over this poem. Combine these frequent erratic rhymes with super short lines and you get a poem that launches surprise attack after surprise attack. Read it out loud, and you'll get the poem's full effect.
"I do it so it feels like hell": POW
"I do it so it feels real": POW
Reading "Lady Lazarus" is a whole lot like being completely mismatched in the boxing arena. Pow, pow, pow, the poem says. The poem's also got tons of internal rhymes (in phrases like "the grave cave ate"). This is powerful, punching language that makes us feel weak in comparison to the speaker. As Plath's readers, we are left whimpering in the corner, while she rises, like a phoenix, from any punch we might throw back.