does anyone know what addon and/or macro this is?

[painweaver]

Click to about halfway into the movie to skip all of his intro crap. You will notice that the chaos bolt spell sometimes switches to soul fire for a second for him to cast soul fire and then immediately switches back to cb. I am not sure what is triggering it or even how this spell is the only one on the main bar that is changing. any suggestions?

http://warcraftmovies.com/movieview.php?id=204633

[Maelandel]

Macro

/cast [nomod, harm] Chaos Bolt
/cast [mod:shift, harm] Soulfire

[gracfuldeath]

Macro

/cast [nomod, harm] Chaos Bolt
/cast [mod:shift, harm] Soulfire

#showtooltip [nomod] Chaos Bolt; [mod:shift] Soulfire
/cast blah blah

the #showtooltip will give you the icon change.