Hi @hawkridgefc 
editing the images themselves to be consistent sizes and aspect-ratios is generally the most reliable method to handle this.
Especially if the store is multi-channel as otherwise a theme can be customized but then on social media, or third party marketplaces the images will still all be inconsistent.
With theme customizations tall or wide images will typically ALL get the lower and side parts cropped.
If you need this customization fixed, then contact me for services
Contact info in forum signature.
ALWAYS please provide context, examples: store url, theme name, post url(s) , or any further detail in ALL correspondence.