It’s probably because of that minimalistic look you used. I actually made similar style in one of my items and it was hard rejected, too.
I like it, but I feel like demand for this type of design is not high – at least from perspective of marketplace reviewers.
So try to redesign your page and use more popular design features and elements and you will get approved. I think you have what it takes, to make it.
Thank You 2F it is really Help