Me neighther

Symbolism. Innocent child with toy horse burned after her mother was cut down by a Dothraki, despite Arya trying to help them. The white horse stained with the blood of innocents leads her to the source of the carnage (the regrouping Dothraki and Unsullied) as well as a fortuitous meeting with her brother with helps serve as a catalyst for the pivotal betrayal/reckoning.

As a middle finger to the hayters