I think I get the title (I do love Marmite) but the composistion isn't working for me here, maybe if you could go lower and focus on just one rose? Otherwise I think the processing works, sort of....
I think the overhead shooting angle makes the shot look a bit flat. A lower angle with more DOF would help a lot imo
I don't like Marmite and I think I would prefer the full colour version. Roses come in so many lovely colours that I feel it's a shame not to see that colour. Some one has to dislike Marmite and it's me - sorry about that.