Questions about NG rewriting

server {

    if (!-e $request_finame) {
        rewrite ^/(.*)  /index.php? last;
    }
    # or
    location / {
        if (!-e $request_finame) {
            rewrite ^/(.*)  /index.php? last;
        }
    }
}

Actually, I want to ask, the two rewriting rules are the same.
But it is written in location / and directly under the server. What's the difference.

If it is written outside, www.example.com/packages/xxx.apk cannot be downloaded.
If it is inside, www.example.com/packages/xxx.apk, as long as the path exists, it can be downloaded.

I didn't know the reason. Please kind-hearted people can clarify this. Thanks