Do you consider the difference between a mosquito and a goose to be "almost irrelevant"?
Let's take a look here. The message being communicated was "google is much much larger than duckduckgo". Metaphor used carried that information. Communication achieved.
What's this about a goose and a mosquito? What's that adding to the communication? Seems pretty irrelevant.
I think it adds a lot. Comparing an elephant and a mosquito makes it seem like the mosquito is almost non-existent. A goose compared to an elephant is much more significant. A goose can stand up to an elephant. [1]
LOL - in a metaphorical / rhetorical contest, yes, the difference is irrelevant. What matters is the sense of overwhelming difference between the elephant and <insert most common animals or insects>.
In this context — absolutely.
Alas, the worrying trend I see more and more lately that people start to have trouble seeing context of anything. Sometimes it can be amusing, sometimes it looks dangerous.
HN comments suffer from these and more.