What does the word "Genievorstellung" mean in following sentence:
In der Genievorstellung der Romantik waren große Dichter über allem stehende Persönlichkeiten.
Source: Der "wahre" Shakespeare
An important concept of Romanticism was the idea of a genius:
The Romantic movement developed the idea of the absolute originality and artistic inspiration by the individual genius, which performs a "creation from nothingness;" this is the so-called Romantic ideology of literary authorship, which created the notion of plagiarism and the guilt of a derivativeness. This idea is often called "romantic originality." The romantic poets' turned their beliefs on originality into "the institution of originality." The English poet John Milton, who lived in the 17th century, was part of the origin of the concept.Wikipedia
This goes back to Kant:
In the philosophy of Immanuel Kant, genius is the ability to independently arrive at and understand concepts that would normally have to be taught by another person. For Kant, originality was the essential character of genius.Wikipedia
In this context we may translate "romantische Genievorstellung" like it is done by others, e.g. Jonathan Bate in The Genius of Shakespeare:
[...] so the Authorship mystery is consequent upon a Romantic idea of authorial genius.
Or, putting it in other words "Genievorstellung" is
the idea of geniality
It means how people thought that geniuses had to be during the period of romanticism.
In the "genius imagination", the imagination people had about geniuses, great poets were people/personalities standing above everything else. Bigger than live. Shakespeare did not fit in this imagination, because of his social background, his unadorned, humble origin.