if you compare the previous chapter to this chapter, you can see his hair is super overgrown meaning its been atleast a couple weeks so in that time (no matter how slow facial hair growth(which isnt that slow)) ATLEAST a stubble has to be seen. and i think the muscles is odd but maybe its just brcause he is super skinny now and its just his bones and whatever organs showing(??)

super skinny and hair unkempt but still looks freshly shaven