Well, during this reviewed “storyboard” process, there is no individual sketching time, but participants do work in pairs to wireframe one specific part of the prototype.

At this point, we had already defined which ideas or functionalities would be in the prototype (during the Decider’s vote). However, before starting the wireframing process, it is worthwhile to discuss a few minutes in order to agree on which content to integrate within the prototype.
(For example, if you want to prototype an e-shop: you can decide that the user is trying to find and buy Black Adidas sneakers size 10…)
So the teams will be wireframing using accurate content and you won’t have any issue bringing everything together into one consistent whole.
This will ensure that you have a complete scenario to test on day 5.