I believe this was a candid shot someone took of him. My other grandfather was in the army during WW2, but I have yet to dig up that photo again. I came across this one today, while sifting through old items. I believe this picture was taken before Pearl Harbor was bombed; the location where he was stationed.
To a person in a photograph? Neither of us know for sure, he looks classicly high, soldiers even back in ww2 used drugs, it's clearly a joke, and it doesn't matter.