The intense heat of the blast basically baked/bleached the stairs instantly, but the part of the stairs that was behind the person was somewhat protected, so it didn't get bleached to the same extent.
My dad says that the closer you get to the actual site where the bomb hit, there are more and more shadows. (He lived in Japan for two years on a mission for our church)
RIP
FUNSTATS!!! WHERE BE YOU ON THIS LOVELY DAY?!