I don't doubt the marching powder destroys noses but to be fair to LMD and her snozzle it typically destroys the inside or septum, not her ski slope. I also don't doubt she is a regular dabbler but I really don't think this is the cause of the change, in fact I don't actually think her nose has changed at all, it's only cause she has less face now to disguise it! Don't worry tho, it's been highlighted that much she'll likely get it done when she inevitably goes abroad for skin removal
Also just to add - it's big but I've seen worse, I don't actually think she needs to do anything to it!!