Your images are of different sizes, so they show like that when you do reviews. You can either resize your images before adding them or try to control the size with CSS styling.
You can try using this in the CSS section of the template:
img {
max-width: 30%;
}
This should make all images to have a maximum width of 30% the size of the container they’re in. You can try playing with that number. Or you can use max-width: 200px; instead (or whatever number suits you), to set a fixed maximum width.