When Sega first brought the Yakuza series to PC back in 2018, pre-orders on Steam would grant users some bonus wallpapers, avatar icons, and a digital manga. This applied to both Yakuza 0 and Kiwami, with the editions being called "Deluxe Edition." If you didn't grab either game during this short window, you missed out on the little bonus goodies.
Thankfully, Sega has come around and changed that. Instead of selling the extra stuff as DLC, Sega has gone ahead and upgraded all copies of both 0 and Kiwami to Deluxe. Whether you've owned the game for years or are just buying it (both titles are still on sale, by the way), you'll be given all of the stuff that came with pre-orders from a few years ago.
If that wasn't enough, Sega has also included some bonus Steam artwork for both titles. With Steam's interface getting updated last year, you can now swap out what each tile looks like in your client. If you want a different poster to stare at, you can change it. Sega has even included a dynamic image of protagonist Kiryu smoking for Yakuza 0. That should look great as you're getting ready to launch the game.
This isn't the most elaborate of upgrades, but the gesture is very much appreciated. With most superfluous content like this being sold for a couple of dollars, Sega could have easily milked this promotion for all its worth. Instead, the company decided to give back to fans that have supported Yakuza.
Maybe it makes that initial pre-order seem kind of pointless, but it's great that content isn't being gated off behind paywalls. The growing trend in the triple-A space is to cut out chunks of a game and charge for features that used to be standard years prior. Yakuza isn't completely alien to DLC, but it also doesn't sell back large portions of older titles.
At any rate, you should be playing Yakuza in some capacity. If a wallpaper on Steam is the reason you needed to jump in, then don't wait anymore. Your life will change for the better: I can promise that.
Source: Steam Community