The key abstraction in #REST is a RESOURCE. Any information that can be named can be a resource: a document or image, a temporal service (e.g. "today's weather in Los Angeles"), a collection of other resources, a non-virtual object (e.g. a person), and so on.
By comparison, the key abstraction in #NOSTR is an EVENT. Any information can be an event: a post, metadata update, and so on. #NOSTR also provides the key assurance of authenticity by requiring that each event be signed by a private key, having a corresponding public key that makes it easy to very and attribute to the actor holding the private key.