That presentation, without hearing Le Zhang actually speak, says:
- Node isn't a platform or service.
- Nose is a JS environment
Both statements provide extra context than just 'environment' or 'platform' by themselves.
For example, I would consider Heroku to be a platform or a service that allows you to run a Python, Node.JS, Ruby or Java environment as well as number of other things.
In any case, they are both contextual terms that can be used by individuals to mean different things. Contact the author and ask him what he means.