In addition to the stuff everyone else is saying, most modern bulbs don't have a vacuum at all.
Most modern bulbs are filled with an inert gas like argon or xenon. Usually at a lower pressure (around 70% of standard atmospheric pressure), but nowhere near a vacuum.
This has, while inert to chemical reaction, is more than capable of transferring heat.
In the American release, the other two ghost sisters just call her ugly a lot. In the OG Japanese, it was more explicit that they were actually misgendering her, iirc.
What's wild is I once purchased a few dozen of those rj45 to serial connectors for a real, on the job project.
They come as a kit thing you have to assemble. That's why it shows them in two pieces in the image above.
They worked, so like, if it's stupid and it works it's not stupid I guess?