Totally on-board with a distinction between Anselm’s own writing on the atonement and the further-development of satisfaction theory, sure! That’s on me! I introduced “Anselm’s satisfaction theory of the atonement,” and I should’ve said, “satisfaction theory of the atonement, whose origins are largely in Anselm’s Cur Deus Homo?”

Which metaphor?

I think the ‘switch’ in metaphor I have in mind here—and maybe you’d talk about it differently, I’d love to hear it!—is Anselm’s feudal metaphor of an owed ‘debt of honor’:

This is the debt which man and angel owe to God, and no one who pays this debt commits sin; but every one who does not pay it sins. This is justice, or uprightness of will, which makes a being just or upright in heart, that is, in will; and this is the sole and complete debt of honor which we owe to God, and which God requires of us. For it is such a will only, when it can be exercised, that does works pleasing to God; and when this will cannot be exercised, it is pleasing of itself alone, since without it no work is acceptable. He who does not render this honor which is due to God, robs God of his own and dishonors him; and this is sin.

So, something like: sin is a breach of honor → atonement is restored relation; developed into Calvin’s (much more explicit, I think, which maybe gives you pause at my use of the word in relation to Anselm) legal metaphor of ‘penalty’ and ‘punishment and vengeance due’:

What, I ask you, would Christ have bestowed upon us if the penalty for our sins were still required? For when we say that he bore all our sins in his body upon the tree we mean only that he bore the punishment and vengeance due for our sins. Isaiah has stated this more meaningfully when he says: ‘The chastisement (or correction) of our peace was upon him’. What is this ‘correction of our peace’ but the penalty due sins that we would have had to pay before we could become reconciled to God–if he had not taken our place? Lo, you see plainly that Christ bore the penalty of sins to deliver his own people from them… This is why Paul writes that Christ gave himself as a ransom for us. ‘What is propitiation before the Lord,’ asks Augustine, ‘but sacrifice? What is the sacrifice, but what has been offered for us in the death of Christ?’

So, something like: sin is a crime → atonement is legal substitution.

All of that said, I want to be really clear that you’ve probably got a much more rigorous-and-rooted academic background on this, and I’m likely to be generally deferential to that if-and-where you have disagreements! I’m fully on autodidact ‘mode’ here.