I believe they were responding to your "confirmation bias, how?" question, rather than the narrative around thermometers. So from that lens, the confirmation bias is choosing to show temperature (objectively measured with assumed-reliable instruments / thermometers), but arguably choosing to hide other kinds/categories of data.
Fwiw, I am not backing them up, since I do not know what other data they might be referring to (and I am not very knowledgeable in topics within climate science).
You're surprised in the context of global warming that the physical quantity of temperature was selected? The temperature quantity itself was cherry-picked?
Does anyone besides you expect them to demonstrate global warming but please without mentioning temperature - that's obviously cherry-picked of course... /s
1 - the area was cherry picked.
2 - only this year's data is highlighted in red - the data from last year wasn't highlighted. It's hard to know if this is a trend or it's just a weird year.
3 - the time horizon is cherry picked. Why mean on a given day rather than the mean for a week?
Imagine someone else cherry picks the line that is really low and highlights it. Or they pick a different area which shows cooling. Now you have some idiot claiming global cooling.
The thing about cherry picking is that it works so well. When someone pointed out the cherry picked data, you couldn't even come to the conclusion it was cherry picked. And you are on hacker news. Imagine the really really silly people.
Fwiw, I am not backing them up, since I do not know what other data they might be referring to (and I am not very knowledgeable in topics within climate science).