The file:

http://www.renderosity.com/assets/javascripts/freestuff.js

Contains an event handler for the download button, which on click, uses JavaScript to open a new window, which is 500 Height by 1200 Width.

Because the window.open function call does not contain instructions for scrollbars, status bar, or other 'chrome' (term used for everything not in the viewport) they are considered to be disabled by the function.

https://developer.mozilla.org/en-US/docs/Web/API/Window.open

If the optional parameters are used, the features that are not listed will be disabled or removed (except titlebar and close which are by default yes).   

In the case of what you are seeing, because only height and width are passed in, everything else is considered to be disabled or 'no'.