Plugin not returning any information

Hi there – thanks for the plugin. I installed it, but I’m not seeing anything useful. After first installing, I roam around the site and I see ‘Featured Image Size: not set’ everywhere I go. Then I noticed there is a ‘settings’ option in the plugin, so I visit that, and I see

‘please set up featured image size. For example, “1200×600” – what’s the point of that? I’m expecting the plugin to TELL me what the dimensions are, so why would I type in 1200×600?

But I typed in 1200×600 anyway, just to comply, and now, I see ‘Featured Image Size: 1200×600’ on every page, regardless of the actual featured image.

Something is not right!