It is funny but it does present the 'logical' reasoning of atheism behind it's claim that there is no God. Does it not?
No. To begin with, the analogy of atheists as babies in a womb is inapt. Whoever created this cartoon cleverly used an image of two babies in a womb because everybody, including atheists, knows that there is in fact life after birth and a "Mom" on the other side. Ergo, by using this image, the atheist comes off looking self deluded and his logic appears faulty and presumptuous.
Now, remove or change the image and change the wording so that it's just two people talking about God and suddenly the atheist argument makes more sense. Or at least it cannot be so easily ridiculed or refuted:
"Hey brother! Do you believe in life after death? Do you believe in God?"
"Nah, I'm an atheist. I mean, have you ever seen God?"
I've never seen God and I've never seen or perceived any indication that there is life after death. So tell me, based on this, what exactly is wrong with the logic I use to arrive at the conclusion that there is no God or life after death?