Sshh. Her lips are sealed.

It's just a stylistic thing, same with the smoke, which represents heat more so than fumes.

Normally you hold the iron horizontal under the nose and of course don't breathe during the heat test.

And you don't actually kiss the soldering iron until it's cooled all the way down, and usually not unless the experimental circuit you came up with works the first time you plug it in :) So you can relax as intended and unplug the damn iron, without having to keep on hammering til all hours.

One thing she's not telling is the way you should be effective enough soldering using (very inexpensive) uncontrolled soldering irons, that you can eventually solder two pieces of solder together. Before you graduate to a "pro-grade" soldering station.