Setting height limit in gallery slideshow in Ishimoto template

I'm trying to set up my slideshow gallery format, and I'm finding that this particular page (first screenshot):

https://laurielandry.com/corporealism

my images are too big. I need it to be smaller, so is there a way to set the maximum height? I tried setting that in the template styles, but it seem to have no effect. 

Strangely enough, I don't have this issues on my other portfolio pages (2nd screenshot).

Reduce height, or reduce height + width? If height only, add this to Design > Custom CSS

div#block-yui_3_17_2_1_1670702074603_3277 {
    max-height: 150px;
    overflow: hidden;
}