I asked my ex if he wanted to see a video of myself that I uploaded, and his response was “Sure why not?” he's still somewhat interested in me?

sounds like you're more interested in him. not judging though

He's being polite, on the edge of being annoyed.

Means nothing. Don't read into it. He's your "ex" for a reason, right? Don't stalk him. If he wanted to be with you, that's exactly where he would be.

I guess just kind of video you plan on showing him

No, he's still a wanker, I'd say.

who knows, why don't you ask ?