Literally moments after submitting this question, I received the answer via a friend:
Wrapping the CSS rule in a "Media Query" would only apply when a screen is larger than 767px (standard breakpoint between mobile and desktop), it would look like this:
<style>
@media(min-width:767px) {
.gallery-reel {
height: clamp(75px, 25vw, 200px) !important;
padding: 17px 0px !important;
}
}
</style>
I can confirm that this worked perfectly! Shout out to support@will-myers.com 🙌