Are the shelf and the door made of the same material?
No, the shelf is made of glass and the door is made of wood.
    src        edge_attr  dst
0     2               on    0
1     3   to the left of   12
2     4            below    7
3     4   to the left of    9
4     5  to the right of   12
5     5  to the right of    6
6     5  to the right of    7
7     6   to the left of    5
8     6            below    7
9     7            above    9
10    7   to the left of    5
11    8            above   13
12    9  to the right of    4
13    9       underneath    7
14    9            below    7
15   10               on    0
16   12  to the right of    3
17   12   to the left of    5
18   13       underneath    8