The core problem: an AI face changes a little every time you generate.
Most AI tools invent a fresh face on every generation. Ask for the same person twice and you get two slightly different people - a different jawline here, different eyes there. This is called drift, and it quietly ruins any project that needs the same character to appear more than once.
Why it happens
A text prompt is not a fixed identity - it is a rough set of directions. Words like "young woman with dark hair" describe a whole category of people, not one specific person, so the model is free to fill in the details differently each time. Even the same prompt with a new random seed lands on a slightly new face.
Why it matters
Drift is why so much AI content feels disposable. A viewer cannot bond with a character that never looks quite the same twice, and a brand cannot build recognition on a face that keeps shifting. The moment you need a series - a story, a campaign, a recurring host - drift stops being a quirk and becomes a blocker.
If you have ever regenerated an image just to get the face back, you have already felt the drift problem firsthand.
The fix is not better prompting - it is a locked identity that the model reuses instead of reinventing. That is exactly what the next lesson covers.