Displayable

A displayable is a term used throughout Ren’Py to refer to things which can be shown to the player, typically through a line like show eileen happy or adding it to a screen like add AlphaMask("feniks.png", "mask.png"). Regular images are displayables, and several structures that combine multiple images into one are displayables, such as Composite or layered images. Ren’Py also accepts colours as displayables (e.g. add "#000" will add a solid black image to a screen), which are automatically turned into a displayable called Solid.

Broadly, basically everything you can display to the user is a displayable to Ren’Py, though if a class or function says it accepts a displayable, it’s expecting you to package it up in a format it can understand like an image path or one of the Python equivalents for screen language statements, like VBox.

You can read up more on displayables in the Ren’Py documentation here: https://www.renpy.org/doc/html/displayables.html#displayables