A speaker watches someone else suffer and says what they see. Tears run down the other person's wrists, which suggests more than ordinary crying and hints at self-harm, though the poem never says so outright. Next comes the image of tall trees that stand only to fall, a picture of strength that seems certain to collapse. It could be how the speaker reads the other person's situation: something that looks sturdy but is already doomed.
The ending is the most striking part. The speaker admits that all of this is only what they see, "you not / what you see." They know their view isn't the same as the other person's own experience, and they can't fully reach what that person feels. The mood is quiet, sad and helpless. The short, broken lines feel like someone choosing words carefully, worried about saying too much, while still trying to show they care and are paying attention.