Catfishing used to be simple. Catfishers, aka people who pretend to look different or be a different person online, used to simply use photos (or videos) on their profile of other people, claiming to be someone they aren't online. Nowadays, with face filters, the veil of reality has become even thinner, allowing people to share photos and videos of themselves, but augmented in some way to appear more beautiful. With a trained eye, it's simple to see the seams of a face filter because oftentimes they are mesh overlays that sit on top of an image or video.
The 'Bold Glamour' and 'Teenage Look' face filters on TikTok are using technology that uses machine learning, aka artificial intelligence (AI) tech, to change a person's facial appearance. Using the filter, every facial pixel is regenerated and then output after referencing a dataset of images. So the filter takes your face and reconstructs it using the filter IN REAL TIME. There's no overlay and no way to tell that this isn't actually a person's real face, which is why it looks so insanely realistic.
So if you're a catfisher, now's your time to shine.