This looks a bit like my 10-year-old Calico in her expression. She's recently taken to exploring the backyard (She was very much an indoor cat before, with what appeared to be Kitty Agoraphobia), and is learning to hunt by stalking... leaves. And Pinestraw. And occasionally butterflies, but they fly away before she gets close. And when she tries to hunt, she has this expression on her face like "I'm a srs hunter. Take me srsly."