the lecturer is saying
we can already make two observations.
it seems that
already is used for perfect tense, so is this expression here grammatical?
"Already" is not only used with perfect tenses:
I already play tennis.
I already saw that film (have seen would have the same meaning)
By Monday I will already be in Japan.
When a verb phrase indicates a state, not an action, you often don't need a perfect tense. The modal verb "can" indicates a state, so it is idiomatic to say
We can already make two observations
We can already have made two observations (grammatically correct, but not a common expression)
I can already speak Chinese. (correct)
I can already have spoken Chinese (odd to the point of being wrong)