Put a shine on it

So on Monday I picked up the girls and they went with me to check on Kaswyn. All I wanted to do was hand-walk him and check his leg and neck, so it was going to be a short trip to the barn for me. On the way there, in the back seat, the girls started discussing horses and barns.

...

Lily: Do you remember Honey?

(Honey was a haflinger pony that the girls had ridden a few times at a different barn)

Macey: Yeah, I loved Honey, but she's not at this barn. This is a new barn.

Lily: Oh right.

(pause)

Lily: Do you remember how white her tail was?

Macey: Yeah, it was great!

Lily: And how sometimes she'd run and her tail would sparkle?

(I'm driving and thinking "What is she talking about?", but I say nothing)

Macey: Yeah, it was sparkly.

Lily: It was sparkly because of the dirt she kicked up. You know, how sometimes when the dirt is in the air and the sun hits it it sparkles?

Macey: Yeah...

Lily: But sometimes there was poo-poo mixed in with the dirt, and that didn't sparkle.

Macey: Right. Because poo-poo doesn't gleam in the sun.
...