Since the quoting function isn't working, I'll just say that this is a response to the first post:
When people say "hotter than the sun", they're usually referring to the temperature of the Sun's surface, which is only 10,000 degrees F. The corona, which is the Sun's "atmosphere", can reach temperatures well over 1,000,000 degrees F. The center of the Sun is well over 25,000,000 degrees F.
Now, knowing that the intensity of the Sun on Earth is about 1350 W/m^2. The video description also say that he used 5000 1cm square tiles. Assuming a high reflectivity of 95% and all tiles aimed perfectly at one focal point, let's say about 1cm^2 in area, then the intensity at that point is:
( (1350 W/m^2)*(5000 cm^2)*0.95 ) / (1 cm^2) = 6.413×10^6 W/m^2 = 641.3 W/cm^2
This intensity is probably around the power of a decently powerful CO2 laser used in industrial cutting (as a very optimistic guess - optimism favoring this mirror's ability).