Wireless electricity transmission, all Tesla-y. Neat! As the article notes, the tech is very clunky, both in terms of design & of efficiency (only 80%). This is only a proof-of-concept type thing to demonstrate that wireless electricity transmission over larger distances is doable, rather than something that's being rolled out to the stores anytime soon.
All of this is made clear in the text. Which, of course, doesn't stop muppetular comments to the effect of "Oh but this is all faily cuz it needs that hueg boxy thing there and everyone knows tellys are getting thinner ha ha". I seriously don't know what is wrong with some people. Perhaps they live in this parallel universe where of all that tedious theory-test-develop-prototype-refine etc stuff is replaced by a system where new technologies just sort of coalesce out of the aether, without any of those boring lumpy intervening steps like oh I don't know building a proof of concept to show potential investors.