Yes, but it’s still embedded on my website (note my logo and such on the top). You should also still see my website address on the top. This is important for SEO as the time the viewer spends looking at the report will help my pages’ ranking with Google. My website won’t get credit for the content since it is inside an iframe, but I’ll get two clicks (one from the first page of my website and then a second one when they are looking at the report).
Having just a login section may actually hurt your SEO if they login from the front page of a website (or the first page they hit) since it will look like it is a bounce on Google’s end (i.e. the website wasn’t interesting, so the viewer left). Having someone stick around for 10 - 20 minutes while going through your report is way better in Google’s eyes as it means there is something very interesting on your website. That equals higher rankings.