Oh Paul

Must be super-rubber to survive the heat of that burn

Well, consider the size comparison of Paul on the model earth, he would not be the same size as he would be in real life. So Paul would also be in the size of the model. So he would be that large, small enough to not be able to see for that fact. That being, the amount if effort he is able to put into a single work day would also be reduced to even a smaller mass than Paul. So this is not a burn, it is in fact, a very accurate and appropriate representation for Paul's effort in this model.