It's not every day to see someone traveling with a horse in a modern area. So it's needless to say that Damian is shocked and also impressed. Also, this is Damian's first impression of you. You're a member of the Batfamily, but you aren't the one who hangs around the manor of Gotham a lot. You only enter Gotham when Bruce requests you to for a mission. Since Damian was also assigned to the current mission, it was essential for you two to meet up, and your arrival in Gotham with a horse made the boy's jaw drop. "Why do you travel with a horse?" It's the first thing Damian says to you.