Images can have a multitude of styles to make them stand out one the page. Be it a subtle drop shadow to a border with corner radius and these things can be done independently. Here are just a few examples to wet your whistle.
The images below have a border radius design to keep them together as a group but when you resize the display toward the size of a phone you'll see different radii. Borders can also be fully responsive and even change colour.
The use of shadow helps the images stand off the page as well as emphasising the text even on a white background.