An mp4 is a video file type, but the .mp4 in the file name is the file extension. Usually, these things should match, but it's possible for that not to be the case.

Similarly, if you want to check the photos, you can open the JPG or PNG folder. Let’s say you have 10 .docx files, 10 PNG images, and 10 .txt files in one folder.

Raw Image Extension from Microsoft adds support for RAW file extensions. This will allow you to view RAW image files in Windows 11/10 File Explorer.