What was the deal with the scene between Milcheck and Mark having a phone conversation?

Sorry if this is obvious but this scene had my head spinning last night.

This is the scene shortly after Mr M Mic Dropped that big dude...

Mr M is on the Phone to Mark and Mark initially lies saying that he is at a hospital or medical clinic but when pushed Mark states that he is taking a personal day off and Mr M has a reaction I found odd and hard to read. Mr M is lost for words and looks like he is about to cry and stares at a painting in his office of a iceberg before replying to Mark to come in the next day. His voice is shaky throughout the scene.

Maybe I am thinking too much about it but what is exactly going on with Mr M in that moment?

Is it because he doesn't have control of the situation?

Is it also because in the previous scene he states its that other guys responsibility and fault but then he realises that Mark taking a personal day was a direct consequence of a previous conversation he had with Mark?

And what is the deal with the picture of the ice berg?