In minute 2:10 Tihomir is not using the process designer but Guvnor. He defines the Work Items in Guvnor and then use those definitions in the designer.
To be able to do this, you will need not only the last version of designet (I think the one you are using is ok), but also the last snapshot of Guvnor (5.3 should come out soon).
Best Regards,