/* Generated by LabelConnector plugin - remove this comment if you don't want the plugin to override your custom label style*/
make_line( 
make_point("auxiliary_storage_labeling_positionx", "auxiliary_storage_labeling_positiony"), --end
make_point("auxiliary_storage_labeling_positionx" + (x(point_on_surface($geometry)) - "auxiliary_storage_labeling_positionx") / 2.0 , "auxiliary_storage_labeling_positiony" ),
make_point("auxiliary_storage_labeling_positionx" + (x(point_on_surface($geometry)) - "auxiliary_storage_labeling_positionx") / 2.0 ,y(point_on_surface($geometry) )),
point_on_surface($geometry) --start point
) 
/* End of generated expression */
