When using the widget in product page, it doesn’t load the widget css. This is why it is working working properly. Here you will need to insert the full css file link to allow the file to load properly.
Click into the page layout html where you have the widget installed.
Here is the default css link for the widget:
<link rel=”stylesheet” type=”text/css” href=”files/theme/prettyPhoto.css“/>
Here you will need to insert your full file address:
<link rel=”stylesheet” type=”text/css” href=”http://www.yoururlhere.com/files/theme/prettyPhoto.css“/>
Insert your site add in place of “yoururlhere” shown above. This will allow the css to load properly in the product page.
Now save your change and re-publish your site