How does code licensing for Unity works? What happens when I post for evaluation / showcase?

I understand there's a space on the forums for this, but I just want to know how the legal stuff works, in simple terms.

What will happen when I post my code to people analyze and eventually suggest better ways to do the same thing? Will it get protected automagically? Will it be open sourced? Should I just not post the code and stick with the binary and snippets?

I'm mostly ok for posting it as open source, I just don't want to get into any trouble.

I think it's up to you. If you post the source, you determine the terms under which you're releasing it: GPL, Creative Commons, "Please do not copy this's proprietary", etc.

That said, people may be less willing to help if they think they could end up getting in trouble for looking at your code and later (unintentionally) reproducing something they saw. That's why the Mono folks, for example, have the following restriction: "If you have looked at Microsoft's implementation of .NET or their shared source code, you will not be able to contribute to Mono."

If you're really concerned about people copying it, I would just stick with binaries and snippets.