The "Smiley" is formed from the expanding cartridge case which is starting to shear/tear the it self apart in the areas which lack case support, namely the feed ramp of the barrel. This area which lacks support allows the case on high pressure rounds to expand to the point of case head seperation if the presses are high enough. Some cases have blown out due to this lack of support which has bled a high pressure jet of expanding propellent gas to blow in to the magazine well and the openings of the trigger gaurd. When this happens the shooter can be hurt and the magazine can pe blown out from the well and in some cases the frames can suffer damage as well.
Click link below to see "smilley"
If you have any cases like the one in the picture...DO NOT ATEMPT TO RELOAD IT!, it has been compromised. Not even the "pushthru dies" will help to correct this...reloading and shooting this case can cause it to have a total case head seperation.
Why? Because the brass has started to shear as it stretched due to the unsupported area. Pushing it back into place will not help the molecular structure.
Don't confuse yourself with what is just an expanded case, swollen looking which filled the loose chamber. Those could be resized, but they will become work hardened sooner than cases which the chambers have tighter dimentions to support the cartridge case better.