All these magazines understood the unbeatable selling power of the Disembodied Floating Head (DFH). Run an ad with text or illustration of a product and you may get some eyeball focus, but drop in a Floating Head and every reader will immediately tear his wallet free of his Sansabelt Loungers and throw bills at the magazine.
Here we see another ad, selling a machine that makes something. Mr. Warner doesn't need to tell you what the product is or how to sell the product his product makes. He doesn't need to, because he's cleverly inserted his own (presumably) Floating Head to prove to you that you need his machine that does something. To remove all doubt, he's also cropped off his own chin. Note that he carefully managed to squeeze in all of his hair. Diabolical! You win this time, Warner! Here's my money! What's the machine? Don't know, but there's bound to be a few still kicking around in basements across the country, now disused because the owners have earned all the money they could possibly need in the last fifty years. I'll just search Ebay for "machine" and buy whatever comes top of the list.