persistent loading icon over first slide

[7yl4r]

On my slideshow the loading icon on the first slide never goes away.

html:

<div id="gallery-slider">
  <img src="img/gallery/original1989.png" alt="Original 14 pulsars recomputed.">
  <img data-src="img/gallery/tooMany.png" alt="ALL THE PULSARS! ">
</div>

I'm loading the slider inside a vex modal which is inserting an iframe, so perhaps that is why I am encountering this issue. Likely not worth fixing, but I wanted to document it nonetheless.