No, I’m not “really” saying that you should stop talking to attendees or to other people in the meeting, but you should use your eyes and ears to catch all the clues from your audience to refocus your content.
Instead of panicking, try to understand if you need to change the tone of voice, the technical level of your presentation, the level of your stories.
You can try changing one thing, and actively check for the results while you’re talking. If you do it with a method, checking first your tone, then the technical level of your presentation and your stories, you’ll quickly find what to change for that particular audience.
And remember, you don’t need to change your presentation to go deeper on lighter on the technical level. It mostly depends on the stories you use, the example you give, the details you explain. Slides are only there for supporting you, not vice-versa.
It takes a lot of practice, but the results will give you confidence, and you’ll deliver better session.