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They mean the 1939 World's Fair. CRTs were about 5" diameter then and very dim.
Scophony showed a 24" TV in 1938.[1] It was mechanically scanned, but, unlike the Baird system, a whole line was illuminated at once, not just one dot. Scophony could produce a reasonably bright image; they even had a projector. But it was complicated, expensive, and needed about 1KW of power for a receiver.
The Eidophor system from 1946 was the first theater-scale projection system. It used an electron beam to write on an oil film, which was then illuminated with an arc lamp to produce an image for projection.[2] All this had to be done in a vacuum, so it had vacuum pumps. For color, three of them were used. Amazingly, it was a commercial success; it was the only bright big screen TV technology until well into the 1980s. Apollo-era NASA had at least four of them in Mission Control. The huge, complex Eidophor machines showed up in stadiums, movie theaters, and rock concerts for decades. It's one of the clunkiest technologies ever deployed.
[1] http://blog.nationalmediamuseum.org.uk/the-last-remaining-sc... [2] http://www.earlytelevision.org/eidophor.html
We forget that television had a "pre-history" of sorts, that TV had been the object of many tinkering since the early days of the 20th Century. In particular, Leon Theremin [1], known for the musical instrument invention that bears his name [2] is credited with demonstrating a TV in 1925 whose resolution was not surpassed until the GE demo at the World's Fair in 1939.
[1] https://en.wikipedia.org/wiki/L%C3%A9on_Theremin
Ah the horizontal hold, had me flash back to needing to adjust it to get a stable picture on UHF channel 20 when I was a kid.