It has a small number of ideas:
There are Actors and Use Cases, and Actors can use Use Cases. I make this a single idea, because it includes notions of what an Actor and a Use case are, and what the link between them means.
There’s a second idea, buts its such a small and simple one, that I don’t think this is a 2-idea diagram. The Use Cases are contained inside a box, which represents the software system we’re thinking about. So maybe this is a 1.5 idea model.