WordPress Themes, Plugins and HTML Templates › Forums › Dicot WordPress Theme › Performance problem: Images are resized in HTML or CSS › Re: Performance problem: Images are resized in HTML or CSS
This practice is normal in Responsive Layout and Retina Ready themes.
To support Retina devices, it is required to set the image nearly the twice of dimension. AND, due to responsive layout, this warning will still be there at different devices.
Please feel free to ask additional questions.