Are there both screens and cell phones?
No, there is a cell phone but no screens.
     src        edge_attr  dst
0      0   to the left of   12
1      0   to the left of   13
2      0  to the right of   26
3      0   to the left of   15
4      0   to the left of    7
..   ...              ...  ...
281   27   to the left of   12
282   27   to the left of   13
283   27   to the left of   19
284   27   to the left of   16
285   27   to the left of   18

[286 rows x 3 columns]