The Targum reports the architecture of the household plainly. Potiphar left all that he had in Joseph's hand, and took no knowledge of anything of his, except his wife with whom he lay. And Joseph was of goodly form and beautiful aspect (Genesis 39:6).
The Sages read this verse as the setup for everything that follows. The Aramaic notes two things in tight sequence. First: the master has stopped tracking his own affairs. He does not know what is in his granaries, what silver is in his chest, who enters and who leaves. Second: the young steward is beautiful.
Bereshit Rabbah 87 hears a moral warning in the order of the clauses. The moment Joseph started tending to his appearance — combing his hair, darkening his eyes, the midrash says — the stage was set for the accusation. The Targum Pseudo-Jonathan, more restrained, just places the two facts side by side and lets the reader feel the tension. Potiphar's trust is total. Joseph's beauty is conspicuous. The only thing reserved from the young man's reach is the one thing that will be used to try to destroy him.
The Sages also hear the phrase took no knowledge of anything of his, except his wife with whom he lay as an Egyptian euphemism: the steward was trusted with every other matter of the household except the intimate life of the master. The Targum preserves the modesty of the phrasing while letting the meaning register.
What we learn is uncomfortable and useful. The places where we have been trusted completely are also the places where a single failure would be catastrophic. Full trust raises the stakes, not lowers them. Joseph has been handed the keys to everything; the test he is about to face is precisely whether keys can open doors that the master's honor has closed.