And this is what the lines of the text in question say; they're from the section of Book I just after Thetis approached Zeus to ask him for a favor for Achilles. I've marked in red the words we would know or could guess at if we had only the papyrus fragment to go on. As you can see, we wouldn't have much of an idea of what the lines said if we didn't have the manuscripts to help us out!

[Zeus] bowed his dark brow in assent, [528]
and the ambrosial locks waved from [529]
the king's immortal head; and he made great Olympus quake. [530]
When the two had taken counsel together in this way, they parted; she leapt [531
straightway into the deep sea from gleaming Olympus, [532]
and Zeus went to his own palace. All the gods together rose [533]
from their seats before the face of their father; no one dared [534]
to await his coming, but they all rose up before him.[535]
So he sat down there upon his throne; but Hera saw,[536]
and failed not to note how silver-footed Thetis, [537]
daughter of the old man of the sea, had taken counsel with him.[538]
Forthwith then she spoke to Zeus, son of Cronos, with mocking words: [539]
"Who of the gods, crafty one, has now again taken counsel with you?" [540]