Hello,

You can either make it flow around the image, in this case please add this code into your custom css box:

@media (max-width: 480px) {
.single_testimonial dl dd {
    margin-left: 0 !important;
}}

Result screenshot: https://pho.to/AeBgK

or image above text. Add this text for it:

@media (max-width: 480px) {
.single_testimonial dl dt {
    width: 240px !important;
    height: 160px !important;
    padding-left: 23% !important;
}
.single_testimonial dl dd p {
    margin-left: -100px !important;
    width: 290px !important;
}}

Result screenshot: https://pho.to/AeBhn

Best regards!