Was the Birthday Diorama sold as a regular set?

No, it was a limited-time gift with purchase above a certain spending threshold, not a standalone retail product.

How big is the finished model?

Roughly 9 by 8 cm at the base and about 8 cm tall, a compact diorama suited to a shelf or desk.

Which colours define the scene?

White, dark turquoise, lavender and medium nougat give it the pastel party look shown in the parts list on this page.

Seasonal

Birthday Diorama

The 40584 Birthday Diorama is a compact LEGO® gift-with-purchase set that recreates a party scene in miniature. Its 157 pieces build balloons, cakes, gifts and a Happy Birthday sign, joined by two celebrating minifigures. White, dark turquoise, lavender and medium nougat give it a cheerful, pastel mood.

Set number: 40584
Year: 2023
Pieces: 157
Minifigures: 2
Theme: Seasonal
Different parts: 56

What can I build with it?

View the official building instructions at LEGO® ↗

Parts list 56

As BrickLink list (XML)

Import on BrickLink: Wanted → Upload, upload the file (or paste its content), pick a Wanted List and add the parts.

Spare parts (6)

These extra parts come with the set in case one gets lost.

Minifigures 2

Boy, White Shirt with Balloons, Dark Purple Top Hat fig-0134984 pieces × 1
Girl, Bright Pink Top, Short Tan Legs, Dark Azure Hair fig-0134994 pieces × 1

Description

A whole party in a small footprint

At roughly 9 by 8 cm and about 8 cm tall, the diorama is deliberately small, but it packs in plenty of familiar party elements within that footprint: balloons in several shapes, stacked cakes, wrapped gifts and a sign reading Happy Birthday. That density of detail makes the small format feel surprisingly complete as a display piece, one that sits comfortably on a shelf or desk without taking up much room.

Two figures join the celebration

Two minifigures belong to the scene and bring it to life, working as a host and guest or as a birthday figure with company. At 157 pieces, the build stays short enough to finish in an afternoon. The 56 unique elements still add plenty of variety between the figures, cake pieces, balloons and the sign, so the building process doesn't feel repetitive despite the modest overall piece count and compact scale.

What the colours show

The parts list on this page shows how white, dark turquoise, lavender and medium nougat spread across the 56 unique elements: white often forms the base of cakes and gifts, turquoise and lavender carry the eye-catching balloon and decoration accents, and nougat shows up in skin tones and a few object details. That pastel combination sets the set apart clearly from bolder City or licensed themes, and it's a useful source if you're after party colours for your own dioramas.

Origin and how it's meant to be used

Like many small LEGO® dioramas, 40584 wasn't originally sold as a standalone product; it was a limited-time gift with purchase above a certain spending threshold. That explains the compact size, sets like this are meant as small extras rather than headline products. For diorama collectors or anyone after a miniature scene for a shelf or desk, 40584 still reads as a complete little model with a clear theme and a surprising amount of detail packed into a small space.

FAQ

Was the Birthday Diorama sold as a regular set?: No, it was a limited-time gift with purchase above a certain spending threshold, not a standalone retail product.
How big is the finished model?: Roughly 9 by 8 cm at the base and about 8 cm tall, a compact diorama suited to a shelf or desk.
Which colours define the scene?: White, dark turquoise, lavender and medium nougat give it the pastel party look shown in the parts list on this page.