@JMinor see mocks posted in updated description. Changes are:

1. Sending data is now defaulted to be on.
2. Title changed to: SHARE MY DATA
3. Blurb updated to: Help Wikimedia make the app better by letting us know how you use the app

I'm leaving the illustration as is for now since I think it's of minor influence but maybe we can revisit again depending on how this change goes.

What about the text below the switch that says "send usage reports"?

That won't visible if it starts in the on position. (it will be saying "thank you")

So we need a copy rethink here as well.

Just updated and removed text below the switch since I don't think it's necessary, the switch is to Share your data or not which referred to on the title and blurb.

While we are at it, shouldn't there be a (small) link somewhere to the relevant part of the app's FAQ or the general WMF privacy policy? Without any possibility to learn about more details, "Share my data" might sounds a bit ominous to some (is the app going to upload all my photos to Commons?)...

@JMinor – considering Tilman's comment, maybe we are overthinking the title a bit still since "share" still implies the user having to do something?

What about rephrasing to be a more passive action to "Allow data collection"?
And then updating the blurb to incorporate a sentence emphasising the anonymity of data collected, plus a "Learn more" link for those really really concerned to go to the FAQs section.