double focus

[color=blue]1-He went to his room with a gloomy look on his face.
[color=red]2-He went to his room, with a gloomy look on his face.

Does the comma in the second sentence imply:
a-the part following it has been added as an afterthought
b-that the sentence gives us two pieces of information independantly and each of them is important (a-he went to his room and b-he had a gloomy look on his face when he did it)
c-could be either of the above.


The purpose of the comma is to indicate a break and in your sentences the break separates the two ideas - ‘going to his room’ and ‘the expression on his face’. There is no greater significance than that.

Note - independently