Picturing Classroom Discourse Analysis (CDA)

We have our own ways in understanding something or make something to be easier to understand.  To understand the CDA, I use multimodal and multisemiotic text to give an easier picture for me. As I know that multimodal and multisemiotic text is a text which
its ways to understanding it are through some strategies such as using picture,
audio, etc. So, below is my understanding about Classroom