I’m not sure what “Telling and Selling” is all about, but the chart appears to reference efforts to increase the number of extension phones. While the photo is undated, I suspect it to be from the late ’50s. The phones themselves are just the thing for bedroom use, the model 500-U “mushroom phone”, a variation that featured a small lamp to illuminate the dial. (To get a better look, here’s the giant version) Thanks go to Dennis Markham for identifying the phones!