Aww

[Bra]

No, he's describing the Hiroshima bombing.

Look, in panel one he's showing he's pointing up at the bomb, and down at Hiroshima.

In panel two, it's like he's doing his little nuclear Kamehameha.

Panel three is -obviously- him making his explosion noise complete with hand gestures.

And panel four, he keeps doing his explosion, 'cause it's big (it's a nuke, yo), but his ear gets tired and falls down.