Calling McMansions “Kleenex box[es]”

I’ve seen McMansions called many things but haven’t seen the term “Kleenex box” before:

Our young builder, with approval from the City, had to chop down a fifty foot street tree to clear the driveway into the garage.  To me, the tree was as important to the look of our street as the structure of the new house itself.  The house is a modernist design, a McMansion in the style of a Kleenex box with huge areas of glass that many readers of this article have seen popping up all over Los Angeles. 

That is one expensive Kleenex box. I’m not sure exactly how the term relates to McMansions: it is mass produced? It is flimsy? It is a boring box? It is just a container to put stuff in? Regardless, the term is not meant to be positive.