When changing the equation from \( f(x) = -|x| \) to \( f(x) = -|x| + 4 \), the transformation is a vertical shift.
Specifically, the graph of \( f(x) = -|x| + 4 \) shifts vertically up by 4 units compared to the graph of \( f(x) = -|x| \).
So, the correct response is:
The original function shifts vertically up four units.