Does the train that looks empty look large?
No, the train is small.
    src        edge_attr  dst
0     0   to the left of    1
1     1            below    3
2     1  to the right of    0
3     1  to the right of    4
4     1  to the right of    3
5     3               on    2
6     3   to the left of    1
7     3            above    1
8     4   to the left of    1
9     5   to the left of    7
10    7               on    2
11    7  to the right of    5