What is an antonym for mural?

There isn't a perfect single-word antonym for "mural." However, depending on the context, some options include:

* Portable: A mural is typically fixed to a wall, so "portable" would imply something that can be moved.

* Small: Murals are usually large, so "small" is a contrasting size.

* Temporary: Murals are generally permanent, so "temporary" describes something that is not intended to last.

* Sculpture: While both are art forms, a sculpture is a freestanding object, unlike a mural.

Ultimately, the best antonym depends on the specific meaning of "mural" in the context you're using it.