Illustrations of the relationship between the LF changes and the penumbral decay/enhancement in the outer/inner regions of the δ-spot, in which its penumbra and umbra are represented by the gray, red, and blue patches, respectively. The plus/minus signs mark the photospheric positive/negative polarities, the dashed vertical orange lines mark the flaring PIL, and the magnetic-field lines from the outer/inner penumbra/umbra are plotted in green/blue. (a) Magnetic-field configuration in the course of the flare reconnection, in which the red field line will reconnect to produce the flare and plasmoid ejection with the cross labeling the reconnection site “RS.” The green/blue arrows indicate the rise/collapse of the field lines from the outer/inner penumbra/umbra. (b) Magnetic-field configuration after the flare, in which the LF changes are denoted by the black arrows and the pre-flare penumbra are outlined by the dashed gray contours to depict their decaying and darkening areas (see the gray/brown text).