Hello, to avoid the Error "Image must have alternate text" you have to add the alt attribute in your image tag. This link(https://www.w3.org/WAI/tutorials/images/decision-tree/) helps you to decide what alt you can use. I also noticed that your image does not change on hover as it have to. To do this you can put your image inside a div container and then use another div container that will contain the eye(The eye image have to be added via css with the background image css property ) that will appear on the hover state.
Chech my solution here(https://github.com/Christ-Kevin/NFTchallenge/tree/main) to get more infos
Keep coding
Christ