Is there a fence or a train in the picture?
Yes, there is a train.
     src        edge_attr  dst
0      0           behind    3
1      0           behind   17
2      0   to the left of   15
3      0   to the left of   17
4      0   to the left of   29
..   ...              ...  ...
231   34  to the right of   16
232   34  to the right of   20
233   34  to the right of   15
234   34  to the right of   32
235   34  to the right of   29

[236 rows x 3 columns]