PHP 7.3.9: Check if uploaded file is an image (I don't care about the format)
The method in question does not use $this therefore you might consider making it static.

Further it is a private method, i dont know of which class, but consider making it a public method of its own class.

The method accepts UploadedFile but it is only interested in the real path. As long as you keep it private it could be ok and simpler to call, but if you ever make it public (as suggested above), you should let it accept string path instead, that way it will be more flexible.

There are 18 constants for the image types, but you are using hardcoded numbers. What If another type is added in the future? Do you want to have to modify your code? Check the exif_ imagetype return value doc. It will never return int that is not one of the constants. return is_int($result); is absolutely enough.