The reason this section exists is pretty well stated in an English case: Holmes v. Governor of Brixton Prison and Another. In paragraph 12, they discuss the law of theft in England, and note that under the law there as it stood in 2004 (and reaching back to principles of common law, which are often but not always shared with the US), deception required causing someone to believe something. A machine has no mind, cannot think, and can't be made to believe anything -- it sees an input and mechanically performs some response in response to that input.
For instance, suppose you were to discover someone's bank account number and printed a check of your own that had that number on it. You then make that check up to look like it's a check from the someone else to you, and deposit it to an ATM; you then withdraw however much is available immediately. In all likelihood, no human will see that check until the victim looks into why they're significantly poorer than they remembered, so no human was deceived. The only things that were possibly deceived were the computers involved in the check-clearing process. But they don't have a mind: as far as they're concerned, they see pixels, pass them through an algorithm, and then send a message to another computer at the bank with certain information (which a human recognizes as an image of a check and an amount of money, but an ATM doesn't know what it means for something to be an image of a check). The machine then mechanically pushes bills out a slot. They don't think the check's real, don't think it's fake, and don't think it's a check: they're just piles of semiconductors and wires acting in accordance with the laws of physics.
If you gave a check like this to a check-cashing place, it's clearly theft by deception: you make the human there (falsely) think you have a legitimate check, and they then pay you money based on it. But these days, a lot of this stuff is automated. Alaska's legislature didn't want you to get out of theft by deception charged because something was automated. So, they said that a machine could be deceived.
This isn't a crime by itself; you can't be charged with deceiving a machine. You are charged with an offense under the chapter that involves deception. What 11.46.985 does is say you can't argue "this wasn't deception because only the machine was deceived."