A Kubernetes scripting engine that runs small Javascript scriptlets. Quickly link API’s together to make your life easier. Autoscaling based on your API? Automator makes it very easy.
OpenFAAS seems to me a true serverless platform to run functions. Automator is much more intended as a small scripting tool to quickly mash up API's in your platform. For example to autoscale based on the number of messages in a queue. I don't know OpenFAAS well enough to say how it compares.
Automator contains a kubernetes client (plugin) so you can easily automate tasks on Kubernetes. But the power comes from bundles a lot of different API plugins so you can mash up APIs. For example, silencing monitoring for certain events based on an internal API.