Here is a really interesting video that explains the process of how they produce those iconic stipple portraits in the WSJ:

“The Wall Street Journal is as famous for its iconic “hedcuts” — the tiny, pointillist portraits that dot the pages of the newspaper — as for its financial coverage. But how, exactly, do you draw one, and why has the Journal embraced them?
The Journal’s Brian Aguilar talked to some of the eight artists who draw the portraits, and produced a video that documents the painstaking, time-consuming process behind them. (Each portrait takes two to five hours to complete.)
Aguilar also uncovered the history behind the use of the drawings — including the fact that they are designed to mimic the portraits that appear on currency.”

Source: The Huffington Post