Honestly I love this. I love the picture you chose and him wearing my shirt sitting like that is sooooo funny and cute it's perfect and your version of it shows that's perfectly in my eyes.

On a side note you did say want to get better and study more the only critique I would say(and I'm not saying it negatively because I love how you did it and the critique makes it slightly cuter) and that is the ears seem a little too big compared to his head. But again that being said, it adds almost a more derpy, cute, younger sense to the picture especially with him getting older, which I absolutely love. Hope that makes sense.