I believe that photo is from S2, Ep 1, which I saw recently. Early in the episode, Miranda is berating Carrie for still wallowing in her post-break-up melancholy. The foursome goes to the Yankees game, where Carrie winds up with a foul ball and they meet "the new Yankee," who asks Carrie out. Later in the episode, Miranda spies her ex and hides before he can see her. I think the outfit pictured above is what she's wearing during that scene. Miranda then realizes she's not as "over" him as she'd thought, and confides this to Carrie in the last scene.