The disciples honour him (Mark 11:7) but also other people (many, Mark 11:8; a large crowd, John 12:12–13). The disciples and others understand this is a special occasion. They throw their cloaks on the colt and on the floor just like a red carpet for a celebrity today. And Jesus accepts the honour they give him.
7 And they brought the colt to Jesus and threw their cloaks on it, and he sat on it.