In Book IV of the Iliad, there are several instances where the translation refers to someone speaking "plainly":
Athena now took the form of a Trojan, the doughty warrior Laodocos Antenor's son, and went about searching for Pandaros. She found him standing among the ranks of targeteers who had marched with him from Aisepos river, and she spoke to him plainly:
"Will you take my advice, and show your good skill? Then dare to have a quick shot at Menelaus! This will give you great credit, and all the Trojans will thank you, most of all Prince Alexandros. [...]"
And later on, a page or so later:
Talthybios went off at once, looking everywhere in the lines for Machaon. At last he found him standing among his own targeteers, the men from Trica. Talthybios came up and told him plainly what had happened. "Quick, Asclepiadês, King Agamemnon wants you, to have a look at our commander Menelaos. Some one has shot him with an arrow, a Trojan or some good Lycian archer. He says it was a fine shot, but bad luck for us!"
(translation by W.H.D. Rouse, 1938)
What does "plainly" mean in this context? I'm assuming there's some nuance that's being lost in translation; why is this speech "plain" as opposed to... not plain? When the speech isn't defined as being "plain", does that have any significance?
What's going on here?