Why is my application's authentication page different to everyone else's?

As per the Authentication Documentation, I'm directing my user's to the following URL to initiate the authentication flow:

https://www.facebook.com/dialog/oauth?client_id=251747341532139&redirect_uri=https://www.facebook.com/connect/login_success.html

However, instead of the login page looking like:

... (i.e. like it does in the documentation and in other Apps I've created and used), it looks like this...

Does anyone know why?

I've tracked the redirects that the page makes, and it's as follows:

1. https://www.facebook.com/dialog/oauth?client_id=251747341532139&redirect_uri=https://www.facebook.com/connect/login_success.html
2. https://www.facebook.com/connect/uiserver.php?app_id=251747341532139&method=permissions.request&display=page&next=https://www.facebook.com/connect/login_success.html&response_type=code&fbconnect=1
3. https://www.facebook.com/login.php?api_key=251747341532139&skip_api_login=1&display=page&cancel_url=https://www.facebook.com/connect/login_success.html?error_reason=user_denied&error=access_denied&error_description=The+user+denied+your+request.&fbconnect=1&next=https://www.f开发者_C百科acebook.com/connect/uiserver.php?method=permissions.request&app_id=251747341532139&display=page&redirect_uri=https%253A%252F%252Fwww.facebook.com%252Fconnect%252Flogin_success.html&response_type=code&fbconnect=1&from_login=1&rcount=1

Application type is set to Native/Desktop, and I've set the App Integration to "Website".

If the language I'm using makes any difference, I'm using C#, and setting the Url of System.Windows.Form.WebBrowser.

As per the above comments, you can use the display parameter in the URL to control which kind of dialog to show, as you would normally do with the JS SDK.

Your URL becomes:

https://www.facebook.com/dialog/oauth?client_id=xx&redirect_uri=yy&display=popup