This message conveyed in this image that heads represents as identifies who he is. This man is not satisfied with himself because every time he replaces his old self with a new self that still not represent him.
I say this because this image displays signs of the man producing many new selves. He can create many selves as much as he can, but there is a possible self that he will feel comfortably embrace it. Every selves he is not satisfied with is replacing with new ones. The almost full-grown heads are probably almost satisfied the man‘s expectation, but they are missing something what the man might lack of. He continues to replace his selves that shows signs of searching who he is.
Despite many selves we are probably not satisfied with, we create ours and search for our comfortable identifies in our deep inside somewhere. Searching for our selves can be painful because we will approach negative results how our selves take action. We might be not happy with our selves whom we create because they do not represent us enough.