The appearance of the Dorito finder was never seen, only the view through it's no-scope. The view looks like the target system of a sniper rifle, but with the name and language edition in text up in its view.
When it detects a bag of Doritos or bunch a of them, a message will appear in halfcapital letters saying "Dorito FOUND!" and the device will make an alarm-like sound.
The Dorito finder is apparently available in multiple language's, as the above text says '*Spanish edition*'.
It's unclear why someone would make such a telescope just to find Doritos, but that's probably part of the joke.