There was more economical freedom in Eastern European countries compared to those incorporated in Soviet empire. At least small private initiative was somewhat tolerated. Also, in countries like Poland communists weren't able to completely suppress religious attachments of populace. They had to accept the existence of alternative, competing moral, and cultural values, and it had the general effect of less-controlled cultural, and private space. Very unlike the strict USSR model where everything had to be in line with central-planned norms.