A convicted rapist (also charged with 91 other felonies) running for president, with as much chance as winning as the other guy.

So in this scenario you're back in 1923?

I'm pretty sure it'd be anything including the words "World War II".

Bonus points if it also includes a date.

"Man fired for criticising homosexuality", or maybe "man imprisoned for refusing to hire black person".

People are thinking about technology, but in 1923 people were very familiar with breathtaking technological change. The complete reversal of some social norms, on the other hand, would be almost existentially disturbing to these dudes who believe in the great benevolent Christian empires, and in some cases thought ending slavery was a mistake.

I have to wonder what the residents of the 1920's third world would think. I'm sure there would be many interesting perspectives.

The Titanic sinking kills five more

Only the richest people have horses. Most just use cars.

That Germany is Europes biggest economy. 100 years ago Europe was fresh out of WW1 and Germany was bankrupted as punishment.

How pervasive surveillance and tracking of people (and their data) is in todays society. We've become accustomed to it but I'd bet people a century ago would be shocked at the idea of stuff like regular people being filmed from multiple angles when just going to the shops, having a device in their pocket constantly recording their location, receiving targeted advertising based on what information they've looked at previously, etc.

Most international experts consider the outbreak of a third world war unlikely in spite of global surges of violence

Not mundane, but the implications would be horrifying to 1923 society still recovering from "The Great War".

Quite a few people would be probably surprised that colonial empires are no more

as for headlines: British PM Rishi Sunak negotiates Scottish independence with First Minister of Scotland Humza Yousaf

Probably all the climate change shit

Also if you told a guy from 1923 that the world's most industrialized nation was China they'd probably accuse you of lying

– “You can freely marry a Black person in most of the civilized world.”

– “Why would you?”

Climate change, same sex marriage (though, perhaps not as shocking as some might expect, ditto anything trans related), potential mars colonization, coming off the heels of the Spanish flu, COVID news would probably freak em out. Ooh, the USSR being gone, and China being a world super power. The USSR would have been new to them, and it collapsing less than a century later would probably feel quite odd, especially if you could make them understand just how incredibly advanced the USSR got in such a short amount of time. Tons of stuff.

Most tram networks and passenger trains have been abolished. Yeah, and you can't walk on the street anymore.

You can buy groceries from a mechanical grocer, but it’ll accuse you of shoplifting like three times while checking you out.

Just an advertisement with a smiling black guy would do.

You can have a heart transplant.

Brexit would have confused a lot of people.

Many countries all around the world possess weapons that could obliterate an entire other country, or their own country if detonated by mistake, and possibly destroy the whole planet.

That I have a device that fits in my pocket and can connect to almost anyone else on the face of the planet, as well as tell me any fact I'd like to hear, or any story I'd like to experience. And it does all this about as fast as my thumbs can type out the request.

Most people spend more than three hours a day staring at a small mirror in their pocket that makes colorful dancing lights.

Anything price related. Imagine telling anyone from 1920s that you paid 50 dollars for a piece of clothing.

There are still no flying cars.

"A N***** WANTS TO BE PRESIDENT. AMERICA HAS LOST ITS WAYS TO INSANITY"

"F*****S PARADE AROUND THE CITY AND THEY WERENT SHOT AT FIRST SIGHT"

"PATRIOT ARRESTED FOR BURNING CROSSES"

"PEOPLE CLAIMING STATE AND CHURCH SHOULD BE SEPARATED ARE NOT FIT FOR OFFICE, THEY ARE COMMUNIST TRAITORS"

That nearly everyone is carrying a tracking device with them, designed to disguise itself as a convenient entertainment device.

Nearly anything from the Onion or Florida

I'd imagine it's the things that still kinda make it as headlines today, but don't get much coverage anymore because everyone is used to it by now.

"By the way, this weekend's mass shootings led to 10 deaths and 29 injuries total, a little more than last week. Parents, remember to bundle up your kids this fall semester with the latest BulletBlocker Youth Jacket, 10% off if you order today! Now back to the news you actually wanted to hear about: the former U.S. President allegedly commits even more crimes..."

humanity generates 16km³ of piss daily.

8 billion people and growing.

1923?

Lenin's body lays in the mausoleum on the Red Square for the last 99 years. Impersonators of him and Stalin walk around in their daily routine, asking money for photoes with them. In a shop not far from them, you can purchaze chinese merchandize with a soviet, russian flags, as well as with a monarchist-sympatising one, even though Romanovs are as dead as they were back then. Some items cost over a thousand of rubles, a sum that was enough to buy a factory - and that's after two recent denomonations. Pretty good that these crowds of international tourists don't count their money being there, these prices can easily drive someone insane.