If you have an image you would like to use as the background to the “Load More” button. Add this to the “Custom CSS” area after changing the url to your desired image.
CSS
#sb_instagram #sbi_load .sbi_load_btn {
background-image: url("http://localhost/demo.local/wp-content/uploads/2013/08/5plantbg.png");
}
This is the url of the image you want to set as the background.