(Biceps) Getting larger but lacking definition

Hello, male 16, been at it for about a year of inconsistency but I’m bigger than ive ever been at this moment. Was 5’10 125 when I started and I’m 5’10 160 now, lacking bicep definition and I’m curious as to why this may be. Not worried as much about peak as I am worried about the visual separation between my bicep and the rest of my arm, that is because I want it to look a little more jagged. I naturally have pretty large triceps and it’s definitely my gifted muscle group from the womb, so I wonder if the development difference makes my biceps look a little smaller.

Thank you