I don't think it depicts (conveys, draws from?) a specific stereotype. It's just self-disparaging humour. There's an opposite self-stereotype, captured by the

I don't think it depicts (conveys, draws from?) a specific stereotype. It's just self-disparaging humour. There's an opposite self-stereotype, captured by the phrase "Polak potrafi" (a Pole can do it), which actually emphasizes resourcefulness as a national trait. Although it's often tainted with irony, or at least implies that the creativity employed isn't really by the books, etc.