How can a manuscript lack confidence you ask?
Well, it wasn't the manuscript so much as the writer.
How can a writer lack confi...oh wait, you know all about that don't you?
In this instance it meant that the writer did not have the confidence to just say something. The something had to be elaborated, explained, or just said again in different words.
That kind of accessorizing undercuts the power of your work.
Just say it.
Have the confidence to let the words just be there on the page.
This is the kind of thing you watch for when revising. Are you repeating something you just said? Which version is better? Keep that one.
Intended repetition is a powerful tool.
And miles to go before I sleep,
And miles to go before I sleep.
UNINTENDED repetition is cumbersome.
Watch for it.
It's not wrong. It's not an error.
Spell check, or even most beta readers won't catch it.
You'll catch it when you're looking at your work on a granular level.
Word by word; sentence by sentence.