Pretty sure it is just the basic "Area Over Farmed" hint:
QUOTE
Because you've
been repeatedly
killing just the first
few monsters at the
start of the map,
these monsters are
starting to run low
on loot. You can
just play through
maps normally a
few times and
everything will
return to normal.
First time farming trolls it looks like, howd you make all that money for your armor and zodiac weapons?
just because hes taken a load of henchmen into the area doesnt mean its his first time farming them. he could have just had an idea for a screanshot and gone and done it.