When you use your mobile phone on iOS or Android, Google and Apple both try to get you to set your home and work address. But now, if you search for certain queries with location qualifiers, Google will ask you to set your home address if you have not done so yet.
If you search with qualifiers such as [near home] or [near work] and other variations, Google will ask you for your home or work address, even on desktop search.
If you are not signed, Google will show you this screen:
If you are signed in, it will ask you to set your home or work address:
After you say okay, it asks you to enter it:
Again, this is not uncommon on mobile but I don't think I've ever seen this on desktop.
Forum discussion at Local Search Forums with the nice find.