Which practice material is this from? Does the material definitely contain this or is this how it sounded to you? Of course, it should be 'we are kind of ...' but it would be said 'we're' - fast and unstressed. So it's possible it sounded very like just 'we' alone. But if you're sure this is really what it said (from a transcript for example), you should probably stop using this resource for your practice. It's not reliable.

This sentence is very casual and not well formed. ...we are kind of largely talking.... "Kind of" and "Largely" should not be together. Using one or the other would be better.

You are correct in your observation. The sentence you provided has a grammatical error. It should be: "When we talk about technology, we are kind of largely talking about ourselves." Adding "are" before "kind of largely talking" makes the sentence grammatically correct.

You are correct that it's not great grammatically. Unfortunately, for language learners, characters don't always speak grammatically correctly.