Evolution of the averaged |B_r| (panel a) and B_t (panel b) for SHARP number 2875 within about three days. Panels c and d: scatter plots of the continuum brightness in Fig. 3h vs. the |B_r| from Stokes inversion and CNN model methods, respectively. The one between the continuum brightness and B_t is shown in panels e and f. The left and right images in panel g being Region R2 in Fig. 2a are the same with the exception that the left part is overplotted with the contour of B_r. The contour levels are 45 and 200 G. The green ellipse E2 denotes the strong network region. Panel h: value of the continuum image extracted from the red line L1 in Fig. 2a, while the blue line represents the corresponding B_r value.