You're right, it's not a good comparison; PSP is a device and Node is an application that runs JS. Though I wouldn't say it's "backwards".
Anyway, the article is saying there is some native host bindings for each platform, which get swapped between PSP and Desktop. However, same JS app code is running on both, calling out to the injected bindings. It's a common pattern for portability of game engines and stuff.
I haven't verified any of this, I'm just saying it makes perfect sense to me. I hope that helps.