All the Layers
The Russian doll is a small wooden box, often with several dolls inside, famous since the early 1900s. The toys within the toys within the toys. Because they are so well-known, we all laughed when the author joked about them being full of themselves. However, when we continued to laugh at the answer immediately below it, the 3rd guy did not find it amusing.
It turns out he didn’t know much about Russian dolls; otherwise, he wouldn’t have gone into attack mode so quickly. I don’t know whether we should be irritated by all the squabbling or relieved that they’ve found someone to stand up for them. We’re not sure who’s winning this debate, but it was entertaining nonetheless.