Buts it not 4K?
3840×2160 pixels = 4k
Yes, it’s 4K.
Photos show a remote being used that has LCD screens?
Oh no. That might be the phone app.
That’s an iPhone. Per the item page:
Chromecast built-in lets you command your entertainment and easily stream content from your phone directly to your display.
Review I read mentioned pretty poor input lag, so gamers beware.