

Streaming was very much the term used to describe watch instantly language (like all language in the UI) wasn’t random, it was the result of continual testing and optimization. The entire set of activities was new for a lot of people, and the company tested variants of everything all the time. I can’t remember too much about this specific device/UI combo, but probably watch instantly was chosen because at the time it needed to distinguish “instant watching” from managing your ‘DVD by mail’ queue (which was the only thing you could do on the web before “watch instantly” was a thing. We definitely used streaming to describe the activity though; you’d find it in press, earnings calls, etc… Just not in that particular variant of the UI. (source: worked there at the time).
It looks like it says iPad in the upper right. iPad never used Silverlight, it had an iOS app from launch, but you’re right in general. PC browsers used WMV for a brief while at the launch of streaming and then switched to Silverlight.