My understanding is that "arriba" = "above" and "de arriba" = "from above". For instance, I would use "de arriba" in:
Si me miras de arriba, no me doy cuenta (= If you look at me from above, I won't notice).
However, I have recently written:
Él dice la frase arriba (= He says the above sentence / sentence above).
A native Spanish speaker corrected it to "la frase de arriba". Why is "la frase arriba" incorrect?