What do you mean by the selection button? do you want to add icons? do you know css?

.img-metadata .ims-label {
border: none;
overflow: hidden;
padding: 5px;
text-indent: -999em;
width: 24px;
background: url("image-url.png") no-repeat 50% 50%;
}

You just have to modify/add the css file. we are woking on a premium theme but there are a few bugs that we need to fix before we release it.