My apologies. Our attempts to implement the plugin have been unsuccessful. Pleas advise on exactly how we can get the watermark to show up on our images. We are having a difficult time. Thank you kindly for your patience with us.
But returning to your questions:
Do you know what are image sizes in WordPress?
Do you know how to use it in your theme or how they are used in your theme?
Do you know how to preview generated image sizes?
What I’m saing is you should get familiar with image attachments in WordPress to make use of the plugin. Because it works, as I showed you above – we didn’t even change any plugin settings. But making use of those images in a theme is a cempletely different thing.