OnLeaks and Smartprix say that the S25 Slim’s camera system will include a 200MP main camera, a 50MP ultrawide camera, and a 50MP telephoto lens with 3.5X optical zoom. The telephoto lens will apparently have a special design:

The Galaxy S25 Slim will be one of Samsung's thinnest smartphones ever, measuring just 6.4mm thick. Even with the camera module, the total thickness only goes up to 8.3mm. In fact, many of the existing smartphones are already 8mm to 10mm thick without their camera modules.