These numbers likely include the retail employees at Apple stores. This is why Apple's diversity numbers are so much less skewed than any of the other tech companies, which are reporting based on a much different employee mixture (i.e. Engineers + Sales and Marketing, vs. Apples Engineers + Sales and Marketing + Retail store employees.. Much easier to pump up the numbers this way.
As to why publish a report saying, look at me, I'm so diverse (at least compared to Twitter, FB, et al.) I would think it's obvious. Risk management from "corrective" action by government, i.e. discrimination lawsuits, regulatory action, etc. Particularly when one's company is so tightly aligned with the democratic party .