These are some Icelandic horses. Icelandic horses are some special breed that they are very protective of, so you are not allowed to bring other kinds of horses to Iceland.
They are tiny, so when you see people riding them it looks like people are trying to ride donkeys around.
I learned the hard way how proud Icelanders are of these horses. When Davið first showed me pictures I burst out laughing and said they looked like donkeys. He got really mad, started defending the horses, then would not talk to me for the rest of the day.
We saw some today and fed them some bread. I guess Icelandic horses like bread, they were even fighting over it and kicking each other. It was kinda like how ducks, or seagulls fight over bread or garbage.