Industry 4.0 introduces innovative ways of professional training thanks to new technologies such as Virtual Reality and Augmented Reality. Despite improvements, there's still a lack of a good user experience and connection between user needs and these applications. To tackle this problem, designers of such applications must work in a collaborative way integrating final users. It's specifically true during design phases such as scenario creation. But the co-creation of scenario is a difficult task for designers and final users who don't have enough expertise with IT. A solution seems to stand in intermediary objects (IOs) which are well known for their characteristics of mediation, transformation, and representation. We have studied the use of different IOs during a project consisting in designing an immersive professional training application for risk hunting for Stäubli company. We used an IO1 made of an excel sheet and an IO2 made of 360 views of the workshop. Two ideation sessions with two groups of designers were conducted to propose a scenario consisting of several risks to spot in the future application. Results show that the scenario was improved using the IO2, and final users and designers were more collaborative.