I’m just wondering about showing some content or not depending om the device. I mean that some content of the the webpage should not be shown if movile device. This is in order to make it lighter for movile devices.
You can prevent images from loading but you would have to use scripting to remove the images from the page before they load. Hiding them does not do this. It simply prevents them from being displayed.
Another popular technique swaps mobile-optimized versions for each image whenever a mobile device loads the page.