Hi There,
If you do have the standard background-image property, then yes you can apply the background-position property (http://cssreference.io/property/background-position/) which defines the position/part of the image that you want to focus.
Unfortunately, what you have now is the backstretch/sliding background which is JavaScript driven.
What do we advice is to hide the sliding background on mobile and then show a single portrait oriented background-image instead.
@media (max-width: 480px) {
/*hide the sliding background*/
.home .backstretch {
display: none !important;
}
/*show a single standard background-image for mobile*/
body.home {
background-image: url(BACKGROUND IMAGE URL HERE);
background-repeat: no-repeat;
background-size: cover;
background-attachment: fixed;
}
}
Feel free to adjust the @media query.
Hope it helps,
Cheers!