Hi Canice, Congratulations for your solution. :)
For changing the images you can use the <picture> tag, for example:
<picture>
<source media="(min-width:650px)" srcset="images/image-product-desktop.jpg">
<img src="images/image-product-mobile.jpg" alt="..." class="...">
</picture>
Read more about this here
/Or another solution is that you can add both to the HTML page, and you can hide them in CSS.
for example:
HTML:
<img src="images/image-product-desktop.jpg" class="img-desktop" />
<img src="images/image-product-mobile.jpg" class="img-mobile" />
CSS:
@media (max-width: 650px) { .img-desktop { display: none; }}
@media (min-width: 650px) { .img-mobile { display: none; }}