This is a bit of a tricky one. When the program starts, the scale decreases as you would expect, however, when the scale reaches 0, it continues to decrease and becomes a “negative scale”. Basically, it flips inside out.
This defies the laws of physics and obviously wouldn’t happen in real life, but a negative scale means it starts to grow again (but inside out).
If you were doing something like this in a real game, you would likely add some kind of a condition that would make the balloon stop decreasing in scale once the scale was equal to zero, but in the absence of that kind of conditional code, it appears to grow.
Here is a previous thread about this, but I’m not sure the explanations there are much different.
If you still have questions, we are happy to see if we can explain it in a different way. Not sure what I have said makes full sense… lol.
Mike