Player model wrong when riding a horse

I summoned a horse with the following command: /summon EntityHorse ~ ~1 ~

{Tame:1,NoAI:1,CustomName:Chair}

, and I pressed F5. I noticed how when I move my mouse around, my head isn't at the right place. I have a picture showing this. I'm using a resource pack. But, I don't know if that matters.