I've heard a 3-pack like that called a branded search before. Do a search for any chain (starbucks, mcdonalds) and you'll see a similar style 3-pack. One with letters instead of numbers, and with no reviews showing. Last February there was kind of a shake-up where it was noticed that there was more of that branded style 3-pack showing for a wider variety of searches, many of them general, and not company specific. I haven't seen much of it lately, at least with the searches I keep an eye on, but they still pop up sometimes.
Here's a thread about it if you'd like to know more.