[pcthrowaway]

Interactive UI components aren't content, though they might affect content delivery.

For example, a Javascript+HTML game might be itself considered content, but within the game the game elements and controls (mouse, player characters, NPCs, keyboard bindings) wouldn't be considered content, whereas images and dialog text might reasonably considered content again.

[betterThanTexas]

I don't see why interactive UI is any less content than anything else delivered over the wire. How would you express a website without it?

it almost seems like the word "content" is intended to connote "profitable and dynamically-loaded assets". Why you would not use that phrase is a mystery.

I suppose that "dynamically-loadable asset creator" isn't a great marketing pitch from the perspective of artists.