This label moves virtually in space.

<div id="label">Label</div>

#label {
  width:100px;
  height:10px;
  position:absolute;
  z-Index:10;
  border:3px solid red;
}

var label = document.getElementById('label');
osmb.on('change', function() {
  var pos = osmb.project(52.52, 13.37, 50);
  label.style.left = Math.round(pos.x) + 'px';
  label.style.top = Math.round(pos.y) + 'px';
});