So it’s the link to the image in the email: when your browser fetches the image, the ip of the request is tracked and location deduced?
Not necessarily but it works the same way. So in an email I can include a link to my corporate banner that will put a picture in the email.
Or I can include a link that has no visible payload that will tell my website you opened your email. And it can count off ticks to let me know how long you had the email opened.
The methodology is the same, so if you stop one you stop both. And if I really wanted to my thing with the banner could include the tracking.