The miniature is Captain Uriel Ventris, a legendary Ultramarines hero - and that's not so odd - but the look is. This is Uriel Ventris as a Primaris Marine, but have a look at the armour - definitely not Mk X plate, and then there's the head, which Games Workshop changed from the initial preview which appears on the box art, to this one we see on the left. Who knows what you're going to get!
As befits a Black Library Celebration, the miniature is here to accompany the book, The Swords of Calth which comes in Special Edition or normal Hardback, which tells the story of Uriel Ventris ascension to the ranks of the Primaris Space Marines. Love Uriel Ventris, then pick up this $30 Bookmark. In further Black Library Celebration we get the 20th Anniversary Edition of Hammers of Ulric in hardback, the new Liber Xenologis sourcebook in hardback and three of the best covers we have ever seen on some Black Library books; Pariah Bequin, Book 1, Penitent Bequin Book 2 Special Edition (which includes the 'Lepidopterophobia - Medea Unbound' short story) and the normal Penitent Bequin, Book 2 in hardback. These are beautiful, especially that Penitent Special Edition. There's also an Imperial Guard novel, Dead Men Walking in paperback and the Black Library Reader's Choice 2021 Winner The Daemon's Curse (Paperback) Malus Darkblade, Book 1.
For trinket collectors there's also the Liber Xenologis Pin Badge Set: Janus Draik Collection. Plus order anything from the webstore this weekend and you get the free Black Library Celebration 2021 anthology.