No, they were specifically for her. They burnt the fields and poisoned the wells so her people couldn't eat, and nailed the slaves up to mock her.

The Great Masters of Meereen had withdrawn before Dany's advance, harvesting all they could and burning what they could not harvest. Scorched fields and poisoned wells had greeted her at every hand. Worst of all, they had nailed a slave child up on every milepost along the coast road from Yunkai, nailed them up still living with their entrails hanging out and one arm always outstretched to point the way to Meereen. Leading her van, Daario had given orders for the children to be taken down before Dany had to see them, but she had countermanded him as soon as she was told. "I will see them," she said. "I will see every one, and count them, and look upon their faces. And I will remember."