Critias's Metaphor of a Painting

In the dialogue bearing his name, Critias asks his listeners indulgence, IE not to be too critical of the veracity of the story he is about to tell. He tells his readers that he's going to be talking about men, not the gods. Because the topic is familiar to his hearers, he is concerned that they will be overly critical. It's easier, he argues, to talk about things that are unfamiliar; then, your hearers are more open to your authority. He gives a similar, though alternative metaphor of painting, to the one Socrates gives in Phaedrus.

Listening to this got me wondering what this request by Critias says about Plato's writing. When he writes about chariots ascending to the heavens, are we supposed to accept his words, since these are unfamiliar ideas? When he writes about Socrates, does he take more care because he knows his readers (at least his readers at the time) knew the man as well as he? Critias is a later dialogue. Some suspect one of the last if not the last, hence unfinished. Is this request by Critias a commentary on his own writing? Plato was such a careful writer we have to at least suspect that he was aware of how it might function as a commentary on his own work.

CRITIAS: “All that is said by any of us can only be imitation and representation. Or if we consider the likeness which painters make of bodies divine and heavenly, and the different degrees of gratification with which the eye of the spectator receives them, we shall see that we are satisfied with the artist who is able to any degree to imitate the earth and its mountains, and the rivers, and the woods, and the universe, and the things that are and move therein, and further, that knowing nothing precise about such matters, we do not examine or analyze the painting; all that is requires is a sort of indistinct and deceptive mode of shadowing them forth. Btu when a person endeavours to paint the human form we are quick at fining out defects, and our familiar knowledge makes us severe judges of any one who does nor render every point of similarity. And we may observe the same thing to happen in discourse; we are satisfied with a picture of diving and heavenly things which has very little likeness to them; but we are more precise in our criticism of mortal and human things. Wherefore if  the moment of speaking I cannot suitably express my meaning, you must excuse me, considering that to form approved likenesses of human things is the reverse of easy.”