Draco had not come to this cafe with the intention of doing anything except eat his lunch in peace, but when he saw Melinda there, he reconsidered that. He hadn't taken much notice of her until recently, but she'd been useful to him before, and he had been thinking about the state of the Death Eaters since his aunt's explosive post earlier. It probably wouldn't be a bad idea to check in with this young Death Eater. His impression of her was that she was probably fairly loyal, or at least good at faking it, but it couldn't hurt to positively reinforce that. And add himself to the number of people she was obeying, who were analyzing her loyalties, while he was at it.
"Mind if I join you?" he asked, standing beside the chair at her table. He doubted she would have dared to object if he'd simply sat down, and if he'd actually had something of importance to talk to her about, he would have interrupted much more forcefully. As it was, however, he didn't expect her to turn him away; the question was just a courtesy.