It was years... long ago, when the nephew in the children's garden was handed over. I was just running for the company. And yes, they showed a few pictures, including Table with three legs.
Then there was approximately such a dialogue (P)lemyannik with (B)educator
What is missing from the table?
P was!
Why the vases?
P. Here is a table with a vase (pointing to the wall, where, among other things, a table with a vase is drawn)
A few important questions
There is no table with three legs.
P is happening! - And points to the corner of the room, where a triangular table on three legs, on which all kinds of papers, manuals and the city phone.

Praise for observation.