"The specimen has been fully consumed."
The English sentence is in the passive voice which puts the receiver of the action in the subject position and leaves the actor (the one doing the action) unspecified.
Klingon doesn't have passive sentences. Who actually did the consuming? In the Klingon sentence that is who should be in the subject position, following the verb. But the English passive sentence doesn't tell us who did the consuming. We can indicate that in Klingon by using the "indefinite subject" suffix -lu'.
In both the English and the Klingon, it is the specimen that is being consumed. In the English passive sentence, that specimen being consumed can go in the subject position. But in the Klingon sentence, the specimen has to be the object, preceding the verb.