Make sure the cursor is positioned at the place you want to insert the image and click on the image icon on the toolbar at the top right of the recipe popup.
You can then select an image from your existing library, or upload new images. This works exactly the same way as inserting an image on any normal post. Just like the normal image insert, you can optionally specify a link to the fullsize image. Once inserted, the image will show in the recipe popup like:
To insert an image you can manually enter the [img] shortcode. The [img] shortcode works just like the HTML <img… > tag. So for example, at the place where you want the image to appear you might add something like:
[img src= "http://www.mysite.com/images/myimage.jpg" width="200" height="200" /]
You don’t need to use the Text/HTML editor – you can add that right in the recipe popup.
You can use anything inside the [img] shortcode tag that you can use inside an <img> tag. So you could have something like:
[img style= "left-margin:50px" src="http://www.mydomain.com/images/myimage.jpg" width="200" height="200" border="0" /]