Hi,
JavaScripts are initialized when the DOM is ready; which requires some time (it is usually in terms of milliseconds on most cases, but looks like yours is too much, that you were able to take screenshot).
There are 2 things affect this;
- Your website's content (JS, CSS, Images etc..) load is to much (means, there are too many things to load in user's browser)
- User's internet connection is slow
If either of these happens the result will be the screenshot you attached. There is nothing you can do about it, beside making your website "lightweight". You shouldn't load too many Js file in pages. See your website source codes and start eliminating the unnecessary load (especially JavaScript files)
FYI: I visited your website and didn't notice this problem.
Regards