Intensity fluctuations in the region with loop-like features. The layout of this figure corresponds to Fig. 4. The left panel shows a zoomed-in image of the green box in Fig. 1b (region iii). Within this region a smaller sub-field e is outlined. This has the same area as the sub-fields in Fig. 4 i and ii. The spatially averaged relative (left y-axis) and absolute (right y-axis) intensity for sub-field e is plotted as a function of time in the right panel. The vertical bar represents the maximum error for the time series (see Appendix B).