Very few cheap models offer possibility to view the pictures in the field. So if your camera is on remote location and you want to view the images on site, then you will have to bring a laptop with you or invest on external photo viewer.
Typically trail cameras have USB connection that allows you to download the pictures and videos to your computer. So when you plug in your camera to your computer shows as an external hard drive.
Rather than unmounting the camera just to get your photos downloaded, it is more convenient to purchase at least one extra memory card so that you can replace the memory card in the camera with an empty one and take the full card with you. Then use a memory card reader to transfer the files to your computer.