Two are the interesting issues that can be seen in this picture. First, the handling of background environment (here, vector data,symbolised by different colours). Second, in terms of data validation, the identification of possible topological errors: in these views, we highlighted (with yellow circles) the areas on the current edit "coverage" (white vectors) that the GIS informs us (by the small squares) that a line is open (not closed, not defining a polygon). So we can examine if there are any unwanted overshoots, undershoots, etc. & afterwards, we can correct them.