Does the tray have a different color than the bookcase?
No, both the tray and the bookcase are black.
    src        edge_attr  dst
0     0      in front of   17
1     0   to the left of    6
2     0   to the left of   14
3     0   to the left of   16
4     0   to the left of   19
..  ...              ...  ...
60   19   to the left of   12
61   19  to the right of   17
62   19  to the right of    0
63   19   to the left of    8
64   19   to the left of    6

[65 rows x 3 columns]