Text is slightly hard to read. The surprised lady caption under the image, as far as I can make it out,

Spoken words by wire? Amazing! That’s how people felt when the <something> was <something>.

The first might be “telephone”. Second one maybe “young”? Not sure. In 1948 she would not be surprised, and telephones didn’t look like that either, so the ad hearkens back to earlier days when voice over a wire would be surprising. The first few ad paragraphs,

In 1882, when Western Electric joined the Bell System, there were less than one hundred thousand Bell telephones and few cities were interconnected. Today there are 29 million interconnecting Bell telephones - carrying more than 166 million calls a day.

Western Electric has supplied most of the equipment for this tremendous growth. In all, Western Electric has made 50 million Bell telephones - over 10 million since the war.