In case someone else stumbles upon this and needs a way to easily embed a logo, this works:
const container = fullScreenRenderer.getContainer();
const linker = document.createElement('a');
linker.target = '_blank';
linker.href = 'http://www.kitware.com/';
const logo = new Image();
logo.src = icon;
logo.style.position = 'absolute';
logo.style.top = '25px';
logo.style.right = '25px';
logo.style.height = '75px';
logo.style.cursor = 'pointer';
linker.appendChild(logo);
container.appendChild(linker);
Though it’d be great to have the CSS handle the styling…