Lightbox

Is there a way to implement lightbox functionality in Rhythmyx?

Where do you want to implement the Lightbox?
On delivery side or Rhythmyx side?
If it is on Rhythmyx side, is it in content editor form or AA?

I want to implement the lightbox in the Preview and AA on the Rhythmyx side.

AA uses dojo and if you use other framework to create lightbox, that may have some conflicts with dojo and may cause some rendering issues in AA.
If you use dojo, then it is fine, add the dojo.js file conditionally in the template so that it gets added only in preview as we add it automatically if it is AA.