Hi Kristen,
I assume it’s the one on this page at the top, https://demos.bloggingthemestyles.com/camer-pro/blog/
We don’t have a specific setting to change each one’s dimension, so you’ll have to resort to using CSS.
Here’s the code that you can add to your child theme or Appearance > Customize > Additional CSS:
#photowall .post-image img {
height: 500px;
}
You can change the value of 500px to match the one of your images.
Does that help?