I am wondering what "a little less himself" means in the following sentences:
I notice Will and Dad sizing each other up surreptitiously. In Dad’s company, oddly, Will seems a little diminished, a little less himself. Looking at him, in his pressed shirt and chinos, I’m worried that to Dad he might seem privileged and glib, very much the ex-public schoolboy.
- Lucy Foley, The Guest List, (2020) Chapter 14
In this part, I am wondering whether "a little less himself" means that he looks like a "lesser version of himself," or that he looks "less like himself," like he looks like a different person.