Hi @doshea Find the unique ID of the image, change "#block-unique-ID" to your image ID and apply the code below:
/* mobile screens */
@media only screen and (max-width: 640px) {
#block-unique-ID{
width: 50%;
}
}
/* tablet screens */
@media only screen and (max-width: 768px) {
#block-unique-ID{
width: 100%;
}
}
Let me know if it works 😉 If you need further help, please share a link to your website and pwd if needed.