IFRS 15-penalty payable to customer

Sir penalty payable to a Customer for delay in the delivery of a good/service as per my exam kit is variable consideration under IFRS 15.

But I considered the same situation as ‘consideration payable to a customer’ which is not in exchange for good/service.

Both the exam kit and myself talk about reduction in selling price, if it becomes payable, but from different perspectives

So would I lose marks here?