This looks like a mini Paper Pro to me.

reMarkable is holding a "special event" on September 3rd, teasing a new product. From the looks of it, and the way they worded the teaser-trailer, it looks to me as if we're getting a smaller tablet, maybe something like the iPad mini version of the reMarkable Paper Pro (which I reviewed here).

I find this personally very intriguing, as one of the pieces of feedback I sent to reMarkable was a request for a smaller device for on-the-go jotting. I still use the Paper Pro mostly for work, but the fairly big size limits where I can bring the e-ink tablet. Maybe reMarkable is about to solve this.