How do we think about postmodernism and culture?

This lecture I actually struggle to understand, I felt it was very difficult to follow, and difficult to get my head around. I'm not to sure why I found it so difficult however I went on to then re-read the PowerPoint's on unilearn and tried to get my head around them, I still struggled as I thought it was very vague online, so I spoke to other members on the course and they helped me. With discussing it amongst a group of us I learn that, the postmodernism is when you can see something within the image that represents something, stereotypically old such as decor, buildings, clothing and colours.