The only thing I could say would be in my own words and believes, which won't be what u would want to say.... I'm sorry but I can't answer that for you it comes from the heart and soul on what your inspiration would be. mine would be to make me and others happy.
The answer is motif :) any reoccurring theme, pattern, idea, image etc. in a work applies to this.
for example, an artist that includes flowers in across all of their work (or a series of it) would be depicting a floral motif. I hope this helps!!