Welcome to the Insert and Image Resize Filter example site!
In order to test these modules out, please login to the site with the login demo/demo. Create a new Article and try uploading an image. After uploading, use the "Insert" button to insert into the post. Then resize the image in the WYSIWYG editor. Note that drag-handles do not work in Webkit-based browsers, this includes Safari and Chrome.
Let's say you upload a 800x1000 pixel picture, if you resize it down to 400x500 pixels, the image will automatically be resized to match the html height and width attributes.
So if this is input:
<img src="/files/images/sample.png" width="400" height="500" />
It will automatically be adjusted to this:
<img src="/files/resize/images/sample-400x500.png" width="400" height="500" />
Feel free to experiement as much as you like. Please be courteous to your fellow Drupalers.