This is the ESO Datamine (April 2021) from the Update 7.0.0 on PTS (Blackwood Chapter). It features future Crown Store items and the next Crown Crate season - Iron Atronach Crates.
As usual, the Crown Store datamine includes new Body and Head Markings, Costumes, Crafting Motifs and Outfit Styles, Mementos and Emotes, Mounts, Pets, Houses, Furniture and other Crown Store items, including the Iron Atronach Radiant Apex Mounts: Black Forge Iron Senche, Sunflare Iron Wolf and Viridian Iron Steed.
There are also new Skins (Cold-Flame Epidermis, Deadlands Excoriated, Hist Tsoko) and Houseguests (Erilthel, Narboth, Stibbons), as well as the Iron Atronach Polymorph.
Another interesting addition are new Assistants who seem to be Daedric Crows of Nocturnal: Baron Jangleplume the Banker and Peddler of Prizes the Merchant.
Finally, we have a glimpse at the likely Q3 Crown Crate season as the Jester Crown Crates textures are in the files now.
Be sure to also check out the Flames of Ambition DLC Crown Store datamine if you haven't seen it already, as some of the items from it still haven't been released yet.
If you want to discuss this datamine with other ESO players, you can join the ESO Model Viewer Discord server.
Keep in mind that these pictures were found in the game files and the items pictured are not officially confirmed. As such, they might change significantly on release or might never be released at all.