It's a reasonable question, and unless the context is clear as to closing or opening, each interpretation is possible, since the pulling (drawing) action can accomplish both opening and closing.
Of course, without any context, it might be said of an artist delineating, in an artwork, the form of the curtains.
There's a children's story called Amelia Bedelia (I think I spelled it wrong, but it's close) about a housekeeper who follows all the directions literally. She makes a sketch of the curtains. (She also puts clothes on the chicken she is told to dress, and puts dusting powder on all the furniture she's told to dust.) Fortunately for the sake of her employment, she makes amazingly good pie, so they