The parcel which kept answering

An original literary non-fiction-style account of wrapping a large parcel with a younger relative.

The bubble wrap arrived as a practical material. My niece immediately identified its recreational possibilities. Before I had measured the parcel, she had discovered a particularly satisfying row near one edge and begun a small, irregular round of applause.

I explained that the bubbles were meant to remain full of air. She pressed another one and asked whether all of them were necessary. I said that this was difficult to establish individually. The parcel sat between us, waiting for the adults in the room to provide an adult answer. As the only available candidate, I drew the wrap towards me.

We spread it over the table. The parcel looked enormous beneath the transparent sheet, as though it had been dressed for a journey through weather considerably worse than anything our hallway could offer. I folded one side over. My niece held it down with an unexpectedly firm hand. For several seconds we worked together in silence.

Then a bubble popped beneath my thumb. She looked up. I pretended not to have heard it, which was a poor choice in a room where the noise was still practically visible. She asked whether that one had been unnecessary. I said that it had been a test.

We finished the parcel. I gave her the offcuts and kept one narrow strip while clearing the table. From the other end of the room came a neat sequence of pops. I answered with a single one, then put the strip in my pocket before anyone could request a second test.

How does the writer use language to create humour around the attempt to behave practically?