How to I find what is hiding an element?

How to I find what is hiding an element?

I'm having a problem where when the page is loaded, a div element becomes
hidden. Developer Tools in Chrome tells me "element.style" is setting
"display: none"
It's not in my css anywhere to display none. I can't find in either of the
related javascript files anything that would hide the element.
I'm totally lost as to why its hidden.
The jquery plugin I'm using is called Supersized.
Edit: Feel free to check out the page I'm working on:
http://www.gingereventsmpls.com/gallery2.html
If you inspect the html, the element that gets hidden is at the end of
this hierarchy:
body->div"controls-wrapper"->div"controls"->div"tray-button"
tray-button is what is getting display:none attached to it somehow.