def getArtFromTag(tag, type_=None):
    """Returns a list of eyed3.id3.frames.ImageFrame objects matching ``type_``,
    all if ``type_`` is None, or empty if tag does not contain art."""
    art = []
    for img in tag.images:
        if not type_ or type_ == img.picture_type:
            art.append(img)
    return art
