What is the device that is behind him called?
The device is a camera.
    src        edge_attr  dst
0     0               of    3
1     1           behind    3
2     1   to the left of    4
3     1   to the left of    2
4     1   to the left of    3
5     2               of    3
6     2  to the right of    1
7     2   to the left of    4
8     2   to the left of    9
9     2   to the left of    7
10    3          wearing    5
11    3          holding    4
12    3      in front of    6
13    3      in front of    1
14    3  to the right of    1
15    4  to the right of    1
16    4  to the right of    2
17    4  to the right of    5
18    4  to the right of    8
19    5               of    3
20    5   to the left of    4
21    5   to the left of    9
22    6           behind    3
23    7               of    3
24    7  to the right of    2
25    8   to the left of    9
26    8   to the left of    4
27    8               of    3
28    9               of    3
29    9  to the right of    8
30    9  to the right of    5
31    9  to the right of    2