Slider images don't load fully on homepage

I have one post that uses the Gallery format (called “Canvas for Wall Paintings” toward the bottom of the homepage). The problem is that when my homepage first loads, it doesn’t make room for the images in the slider. It is only after the first couple images scroll through that the slider gets big enough (meaning that the other posts have to rearrange during this time as well). This is really frustrating, visually, and makes me want to give up using the Gallery post type.

I have had other posts in the Gallery format that did this as well (I changed them to other formats). It seems that different browsers load differently – Firefox seems to be a bit better than Safari, for example.

Thank you!