In truth, Lexie's statement about what they're looking at was correct.
At the moment it looked just like a normal simulation.
However, the Researcher who was testing the prototype device also had some apparatuses attached to his body to monitor the change that would happen in him.
It was a combination of their two technologies wherein by fighting whatever they generated inside the simulation, one would be able to absorb the stored Source Energy in the storage attached to the processing unit of the device.
The screen next to what's happening inside the simulation was monitoring his vitals as well as his absorption of energy.
Lexie's reaction to it was normal for a World of Meta's denizen.