Staff: "Um...Y is over a month before the exhibition finishes, and when the loan was arranged you agreed to it being here until the end of the exhibition."
Artist:"Oh. Is it really that important for X to be on display?"
Hang on, I can work with this...
Staff: "...oh yes, people have loved it, the public are really surprised to see it and it's had a lot of positive comments."
Artist:"Perhaps it would be best to keep it on show until the end then..."