Well, no, these are different. They are pinned to the poster's page, not mine.
I am suggesting to let Dell throw a tweet at the top of my feed when I next refresh it (and then let it fall down as usual), but unlike existing promoted tweets do it only if I follow Dell.
The "Promoted Tweet" pinned on top of brand pages is auto-expanded, so realistically most companies will probably be using it to showcase a video or graphic rather than trying to engage in 140. Oh well.