so when you upload, you upload your compiled css.
calyspo compiles your sass as soon as you save a file, so in short:
as soon as you upload to the cloud, what is local will be in the cloud (your compiled css)
hope this makes sense haha :D
When running Calypso and saving changes in the SCSS files. The CSS is automatically compiled.
So when committing the work, the compiled CSS is also committed.
No need for another proces.