It's your reflection glossiness setting. I assume you loaded this floor material from a preset vismat your may have downloaded. You want to go to the material editor and for the floor material, change the glossiness setting to 1.0 for very sharp refelctions or use something like .9 for a slight blur which is more realistic. Remember that if you use a number less than 1, that you need to adjust you subdivs, the higher the better but the longer the render times. I use 18-22 for high quality stuff.