What Difference Does Casting Mode Make?

Hey all, I was hoping to get some help with something I couldn’t figure out on my own. One of the skills on paladin, Sword of Justice, has the modifier Enhanced Strike and part of it is that it changes the skill to “casting mode”. So far as I can tell, all it does is add a channeling bar on screen when I use the skill.

Does anyone know what casting mode actually entails? Thanks.