Reflective boundaries implementation

[myradio]

From the JOSS,

Reflecting boundary conditions can be used to improve reconstruction accuracy. For example, with data drawn from a log-normal distribution, a standard KDE will produce ‘leakage’ outside of the domain. To enforce the restriction that f(x < 0) = 0 (which must be known {a priori}), the kernel is redefined such that KH(x < 0) = 0, and re-normalized to preserve unitarity1 . This example is shown in Figure 1, with histograms in the upper panel and KDEs on the bottom.

Isn't this then absorbing boundary conditions? Or am I missing something?