Can I do this? Can I read up from the bottom of this panel to the top? Look at the actions described in the caption: flung, laughed, saying. Read and digest the caption as you would any old caption. Then read the image from the bottom up: there's Abraham on the ground, the white aura is his laughter, and then comes the thought balloon -- just as the caption ordered. I am uncertain about the aura as laughter equation simply because Crumb is so promiscuous with his auras in The Book of Genesis. Could be a run of the mill aura. You never know.