User Story #8 The img element should responsively resize, relative to the width of its parent element, without exceeding its original size. This means you need to set the width property of the image in percentage for example 100% which means the image will occupy 100% of its parent. So, if you have a div as the parent of the image and you set the width of the div to 400px it means that the image inside of the div will also bee 400px in size.
User Story #9 : The img element should be centered within its parent element.
This means you need to place the image in the center and we usually do this in our style tags or CSS file. A simple approach would be setting the margin-left and margin-right of the image to auto. You can learn more about CSS Margin Here.
I hope this helps. Let me know if you need further clarification. Welcome to the FCC community and Happy coding !