theSLAYER

When you select Scan QR Code from your in-game menu, you can register Pokémon as Seen in your Pokédex.
Players can go to their registered Pokédex Entries, to share QR codes for other players to scan.

These codes were generated so that players can have them Seen in their Pokédex.
Can be useful for finding their habitats in the dex (if they are in the dex), or having them show up in GTS search function without having to type it's name.
Credits to SciresM for generating them.

When Pokemon X & Y was released, a dedicated website for international players went live online, with the url www.pokemonxy.com.
However, with the website now redirecting to a generic page, the images might become lost to time.
As of writing, Japan's XY-individual site is still online (http://www.pokemon.co.jp/ex/xy/), but at some point it might go offline, so the images are archived as well. Additionally, certain XY-limited images were also included, for archiving sake.
The style of artwork I use for the Event Gallery was inspired by this splashed-style.
Apparently, the splash artwork in the background is slightly different between international and japanese versions.

International ver. VS Japanese ver.
These images can be downloaded together here .

When you select Scan QR Code from your in-game menu, you can register Pokémon as Seen in your Pokédex.
Players can go to their registered Pokédex Entries, to share QR codes for other players to scan.

These codes were generated so that players can have them Seen in their Pokédex.
Can be useful for finding their habitats in the dex, or having them show up in GTS search function without having to type it's name.
Credits to BYF9 on Reddit for taking the time to snap various screenshots of the Gen 7 entries.

When you select  Scan QR Code  from your in-game menu, you can register Pokémon as  Seen  in your Pokédex.
Players can go to their registered Pokédex Entries, to share QR codes for other players to scan.

These codes were generated so that players can have them  Seen  in their Pokédex.
Can be useful for finding their habitats in the dex, or having them show up in  GTS  search function without having to type it's name.
note: if the image says “JP 3DS only”, you’ll need a Japanese 3DS. Additionally, as these entries are not in the Alolan Dex, they’ll be marked as seen (despite not being visible in the Dex) and can be searched on GTS (their name appears under the alphabetical search, meaning users won’t have to type in their names). No other function.

Credits to @NinFanBoyFTW for the Hi-res scans

A repository for random distribution devices used across the years.
Quick rundown of the images that we have presently

Gen 1 (VC)
UK VC Mew Redemption (and Save Restore screen on the distribution device!)
JP VC Mew Redemption

Gen 1 & 2 (Retail)
Toys R Us security sealed Mew Cartridge and Gameboy
Mew and Celebi Machine (and article)
Spaceworld Mew screen (has different sprite than standard Mew)

Gen 3
Pokémon Day 2004, Germany - Multilingual selection screen (Eon Ticket?)
Aura Mew Distribution Device
10ANNIV/10 ANIV Distribution Device (Groudon GBA SP and Yellow GBA SP)
Pokémon Festa 2005, Japan - Festa Metang Device and Redemption
Mystic Ticket Distribution, Japan
European Shiny Zigzagoon
Old Sea Chart Redemption (device can't be seen)
Gen 4
Crown Entei (Slot 2)
Regigigas Redemption Video (Slot 2)
Battle Festa, Diamond - Magmar (Slot 2)
10TH Deoxys (Slot 2)
Misc. Distribution carts (User YoshiMoshi's collection photograph)

Gen 5
Misc. Distribution carts (User YoshiMoshi's collection photograph)
Gen 6 & 7
Various distribution 3DSes:
Movie 18, Korea
PC Birthday 2017, Japan
Pop-up Store Charizard, Korea
WCS Mew, Korea
Eevee Friends, Korea
Melemele Shiny Tapu Koko, Korea
Worlds18 Meloetta distribution relay

When you select Scan QR Code from your in-game menu, you can register Pokémon as Seen in your Pokédex.
Players can go to their registered Pokédex Entries, to share QR codes for other players to scan.

However, for certain Pokémon, when you try to generate a code in-game, it'll give the "This is a special Pokémon. There is no QR Code." message (as seen below).

This album hold such entries. Their QR codes were scanned from Japanese Ga-olé disks, which was marketed as being able to be scanned into SM and USUM. However, these QR codes are region locked to JP consoles only.