Subtraction maps to assess structural changes in 0954+556. The images in Figure 3 were convolved to a common restoring beam, corresponding to the beam from the observation on 13 June 2016. An average image was generated by taking the mean of the four epochs (2002, 2004, 2005, and 2016). Each individual image was then subtracted from the average image to highlight deviations. The color bar represents the intensity in units of mJy/b. The subtraction maps shows the intensity differences range approximately from -15 mJy/b to 15 mJy/b, indicating a stable structure of 0954+556.