def METHOD_NAME(self, image_type):
    """
    When the type of IOU device is changed.
    :param image_type: type of image (L2 or L3)
    """
    if image_type == "L2 image":
        #  L2 image
        self.setPixmap(QtWidgets.QWizard.LogoPixmap, QtGui.QPixmap(":/symbols/multilayer_switch.svg"))
    else:
        #  L3 image
        self.setPixmap(QtWidgets.QWizard.LogoPixmap, QtGui.QPixmap(":/symbols/router.svg"))