Among students of culture, Finnish reticence and taciturnity are legendary and it isn't a cruel stereotype imposed by others, the Finns recognise it in themselves and it is a source of self-deprecating humour (thus the cartoons).
They also recognise it in others - the "Very British Problems" series (particularly the British horror of unwanted social interaction) would be very familiar to them.
Old jokes from a former Finnish colleague:
An introverted Finn looks at his shoes when he is talking to you, an extroverted Finn looks at your shoes.
Two Finns meet in a bar.
The first Finn buys two beers and they drink in silence.
The second Finn buys 2 beers and they continue to drink in silence.
The first Finn buys another 2 beers and while they are waiting, the second Finn says "How is your wife?".
When the beers arrive, the first Finn says "Did we come out for a drink or to discuss my personal life?"