/ow_themes/simplicity/mobile/base.css - Line 3384
/ow_static/themes/simplicity/mobile/base.css - Line 3384
Should be as follows:
.owm_index_photo_item a {
background-size: cover;
display: inline-block;
}
Also at Photos Page (www.yoursite/photo) the thumbnails should include a background position of "center center"...
/ow_themes/simplicity/mobile/base.css - Line 3006
/ow_static/themes/simplicity/mobile/base.css - Line 3006
Should be as follows:
.owm_photo_list_item a {
background-position: center center;
background-size: cover;
border: 1px solid #ecf1f6;
display: inline-block;
vertical-align: top;
width: 100%;
}