Here is the AVHerald article
http://avherald.com/h?article=4414b816&opt=0which reports they needed a brake check on landing and speculates that the flap extension wasn't standard, thus leading to a higher touchdown speed, thus leading to heavier brake usage. Another possibility might be that the spoilers or thrust reversers weren't usable for some reason, which would require far heavier braking than a normal touchdown.
As detailed in the AVHerald, "configuration" refers to all the equipment on the airplane like flaps, slats, gear, spoilers, thrust reversers. Something didn't work properly getting set up to land, but there isn't anything in the clip that would indicate exactly what.
In order to get equipment in place to meet the airplane, and guard against a possible tire fire situation (like the one reported here a few days ago on landing), the captain declared an emergency. That is the magic word that gets that support in motion.