Hello Albert.
Thank you for your interest in Zedity.
About your questions:
– With Zedity you can insert a “Page” (or call it content if you wish) inside a Blog post. The Page Size, is the size in pixels of the content that you are going to insert in your Blog post. So if you have a size of let’s say 500×500 pixels, you will insert in your blog post a block of content 500 pixels wide x 500 pixels tall.
– Is this happening inside the WordPress editor or once you publish the post? This might be related to the template you are using, if you can give me a link to your blog post, I can advice you or release a fix in the next version.
Yuri