The layout decides how many panels there are, and that decides how many blocks to ask the model for. Panel copy is shorter than slide copy: every panel is on screen at once, so each has less room.
Leave it empty and I will build an abstract underlay from the post's subject. Whatever you write here is what gets drawn — the post's subject is not mixed into the prompt. A Russian description is translated to English first: the Horde models read only English and draw something of their own otherwise.
Up to 12 MB. The picture is cropped to each platform's shape.
Everything you have generated or uploaded — close the tab, think it over and come back without spending another generation.
This is how the background sits under the text.