You need to blend the edges on the marijuana plant. It looks like it was just pasted in without any care. The bottom middle figure is too blurred, you can only just tell it is somebody with their finger out. And adding that Marijuana plant to the top ruined it even more, it again looks like you just pasted it in without care.
You need a lot of work, your work is way to simple and almost anyone could do it. But good attempt, we have a few tutorials on this site if you need any.