The theme of the posters in this collection is propaganda, social awareness, and public service announcements. Does it pertain to that at all?

It does.

I did a little digging on this because I was fascinated by your question ─ it's so off the wall that it immediately grabbed my attention. According to the catalog record, the trademark holder is Yippy Inc. Searching for that, I found quite a few more examples on the LOC prints and photographs catalog. Now, what I found is pretty interesting. While I didn't specifically find something that stated who the author of "Chicken Delight" is, that catalog entry for Yippy Inc. does include a pair of notable items for which the authors are known.

The Nixon and Agnew photomanipulation, the Nixon countdown calendar and other non-catalogued works (out there is a "Dean's List" that's a creative rebranding of Nixon's "Enemies List") are the work of Philip Lief and Marcel Feigel. (There's also a lot more.)

Now, I hadn't heard of these guys before, but they're notable enough that one of their works is up on display in the Smithsonian's National Portrait Gallery. Digging a little more, I found a copy of the March 5, 1973 New York Magazine which describes Lief as a "free-lance designer."

Now, from the name of their company (it might be theirs or they might just be associated with it, I'm not sure) and their activities, it's pretty safe to put Feigel and Lief among the members of the Youth International Party or the Yippies. This was a pretty loosely defined group firmly among the counterculture movement of the late 1960s and early 1970s.

David Armstrong, in A Trumpet to Arms: Alternative Media in America, calls the Yippies "media guerillas," and that's a pretty apt description. These were folks who started alt-weekly newspapers, who built pirate radio stations, who distributed leaflets and got their message across with elaborate pranks and art displays designed to provoke thought. Their work frequently contained non-sequiturs, things like the poster you found, that are designed to make you stop, look, and laugh at the ridiculousness of it all.

The Yippies were both successful and complete failures. While they never made a big difference politically, their influence on pop culture has lasted. Think of the spread of absurdist humor. It's so ubiquitous now that it's unremarkable: In some way, large or small, that spread was encouraged by the Yippies.

If you browse through US magazines- especially Rolling Stone, Ramparts- circa 1970, there are adds for posters like this, typically two pages of thumbnails. As a kid , I saw plenty of walls decorated with posters like this- framed, if somebody had some money, unframed if they didn't. Lots of jokes, sometimes about politics ( Nixon and Agnew were popular) sometimes about sex. Some of the images became popular enough to be iconic, like Huey Newton of the Black Panthers sitting on a throne.

Chicken Delight is something people would eat...you would expect to see it brought to a church dinner in the midwest.