Within the company I work for, although I am not directly involved within the design review meetings, I have spoken to a couple R&D engineers who partake in these meetings. They describe the culture as stressful. The meetings generally are always of high priority to get a design submitted to the proto-type shop in order to test it within the design labs. The meetings generally are rather straight forward without much joking around and every design is challenged regardless the level of engineer presenting it. In some ways it is good to have your design challenged from multiple viewpoints because it will ultimately be better for the design in the long run. However, I was told that within design review meetings the engineers need to possess a certain degree of grit otherwise their design will be completely blown off and pushed to the side.