Su ye's mechanical box was not vague. The one he gave Ling Wen was different from the one he gave his father.
The one he gave to his father was usually empty. He could only see what was inside by pressing on a specific pattern.
As for the one for little Ling Wen, if you don't press the specific pattern in order, it can't be opened at all, just like a solid.
The patterns carved on it were very complicated, and there was no way to explain how to open it verbally. He could only wait for her to open it personally.
Bo Yunli placed the wooden box on the table and rubbed the back of her neck with his finger. He had a half-smile on his face."No one can open the box you made except you."
God knows how many people he had sought out just to open this box, but none of them were of any use.