There is a difference between motif and theme but the author may not be using dominanta kompozycyjna in its technical meaning. Here, it sounds like a a recurrent compositional motif.

ccccccccccccccccccccccccccccccccc
Dominanta kompozycyjna – nadrzędny element kompozycyjny dzieła literackiego, któremu podporządkowane są pozostałe (np. podmiot liryczny w liryce lub fabuła w dramacie). Mogą to być trzy najważniejsze wyrazy lub zdania.
https://pl.wikipedia.org/wiki/Dominanta_kompozycyjna



ccccccccccccccccccc
motif

a distinctive feature or dominant idea in an artistic or literary composition.

cccccccccc

Motif and Theme
In a literary work, a motif can be seen as an image, sound, action or other figures that have a symbolic significance and contributes toward the development of theme. Motif and theme are linked in a literary work but there is a difference between them. In a literary piece, a motif is a recurrent image, idea or a symbol that develops or explains a theme while a theme is a central idea or message.

--------------------------------------------------
Note added at 23 mins (2016-09-30 21:00:57 GMT)
--------------------------------------------------

see http://literarydevices.net/motif/
ccccccccccccccccccccccc