I've read multiple sentences, mostly from articles that quote someone or thing, in which something is said and then a word is in brackets. For example: "And then [she] said..." Why do people do this and what does it mean?
When doing this, they are simply revising a sentence to make it make sense in the context they are saying it in.
If a direct interview says, "Then I took it from him."
An article quoting that interview might say, "Then I took [Tom's shirt] from him."
It's simply to show the audience what is happening in that sentence without having to include the whole context of the story. Does that make sense?