Mobile Site Showing Black Boxes around picture

Site URL: https://www.divastudioanddayspa.com/

One the mobile site pictures I have uploaded are showing a black box underneath, like they are sized incorrectly. I have resized in photoshop based on sizing guidelines. Any suggestions?

Add to Home > Design > Custom CSS

@media screen and (max-width:767px) {
.homepage #page section:first-child {
    min-height: unset !important;
    height: 240px;
}
}