There is a solution that (i think) would look decent on pages with background image.
1. Change icon clipping from circle to square with
.round-div {
-webkit-border-radius: 0;
-moz-border-radius: 0;
border-radius: 0;
}
2. Set the .round-div border-color to something semi-transparent using rgba(). Example (white 50%):
.round-div {border-color: rgba(255, 255, 255, .5);}
3. Change the proportions of featured pages icons to squares (you don’t really have to do this, but I think this solution would look better with square images): 250×250 or 270×270. You might find in theme FAQ a topic on changing icon’s sizes and you will also have to tweak a bit with .thumb-wrapper dimensions on different widths to make it look right.
Alternatively, if you don’t feel like doing that, you could hide the non-square icons imperfections (visible on hover) by altering the scale factor of .round-div on hover:
.widget-front.hover .round-div, article.hover .round-div {
-webkit-transform: scale(1.65);
-moz-transform: scale(1.65);
-ms-transform: scale(1.65);
-o-transform: scale(1.65);
transform: scale(1.65);
}