In my application, I use list to display the items. I have a web service result and i bind with list and adding image in to that list. so I used class as ui-li-icon but it comes with overlaps the value. see the image 
listItem.innerHTML = "<img class='ui-li-icon' alt='No Image' src='"+
g_listOfBusinessDetails[i].imageURL +"'/><a href='#'
data-role='button' data-theme ='e' id='" + i + "' rel='external' data-inline='true'>" +
"<h3>"+ g_listOfBusinessDetails[i].name +"</h3>"+ "</a>";
add style with margin-left to the text , style=’margin-left:some pix or em value according to your image size’
change your code little bit like this
Thanks.