Thanks for the chapter!
I think she's doing the duel to reduce his stars lowering his standard of living as indicated by star explanation and also to make him confess. Also, I don't think the 6 secs from 60 secs is to his advantage. Likely it means he only has six secs to get her to show an emotion and lose while being able to express any emotions he wants while she gets a full minute to loosen up and try to make him lose. Also, makes it harder to keep track of whose turn it is as it switches from 6 secs to 60 and so forth instead of every 60 secs.
@Tamerlane Reasons likely first sentence I wrote here. Although if the one making the application, MC, gets to set the terms why did the phone skip it and allow her to set the terms? Or did he fill in something random in the box after got phone and was suppose to change terms before submitting application for duel hence why it was taken as him allowing her to set the terms?