Facebook registration button adds 1 second to page load

When you activate the facebook login, page loads take an extra second. Why does it take an additional second to load a simple login button?

Home page with ES toolbar module without Facebook registration enabled
http://screencast.com/t/jz9EloDW6b - 1.58s (onload 1.61s)

Home page with ES toolbar module with Facebook registration enabled
http://screencast.com/t/8ASOgQDo - 2.57 (onload 2.71s)

Dashboard with ES toolbar module without Facebook registration enabled
http://screencast.com/t/gCtskkFgUEP - 1.19s (onload 3.17s)

Dashboard with ES toolbar module with Facebook registration enabled
http://screencast.com/t/3vY4y0XpB1 - 2.29s (onload 3.85s)