Diagram looks about right ... basic idea is keeping the head from moving.
How far are you moving the printer? As long as you have control of it and make sure you can keep it level the blue thing really isn't necessary. Basic idea is not letting the head slide around but as long as you turned the printer off so the head sealed, I don't think it can move much anyway.
Most people don't save the device meant to hold the head, and I've moved dozens of epsons without it. These are all short moves, normally the printer is unlatched from the stand and put in the back of a large SUV.
Normal procedure for me is remove all ink cartridges (I never drain the printer), relocate the printer, immediately replace them and turn the printer on, run a nozzle check and make sure all nozzles are clear (clean if not).
If you are having to ship the printer, another story entirely and yes the blue thing or some other way to lock the head down would be important.