Google, one for two

In mysteries solved.

1. News article recently about a man whose smartphone was stolen along with his other valuables from his car, so he called the cops and used a "find my phone" app to make the thing ring as the perp walked right past the cops. What was not clear to me was what he used the app on. His phone was stolen! Did he just happen to have the app on some other device that wasn't stolen? Did he borrow a device from the cops, or from J. Random Stranger, and did the app already have to be on it? I asked that question in comments, and was told I was a fogey who should just Google it. So I did, and it didn't answer the question. From the descriptions of these apps, it sounds like you put them on the device that might be stolen. But then how do you access the app when you actually need it?

2. On the other hand, I successfully Googled a non-textual pop culture query. The only TV I watch these days is Daily Show clips on the web, so the only commercials I see are the ones preceding them. This means I get some ad-based jokes, but one of the current ads was itself a mystery. It's a Pepsi commercial in which a woman walks into a dance rehearsal hall, but in all the reflections she sees of herself in the mirrors, she's wearing different clothes. She dances with the reflections a bit, and then all the glass explodes. I got the feeling this was a reference to something I didn't get, but I couldn't figure out what. To my surprise, Googling "pepsi commercial dancer" Explained All, including who the woman was, and what was with the clothes. (Yes, I've heard of Beyoncé, but obviously I wouldn't recognize her if she passed me on the street. I don't know any of her songs, and all I know of her offhand is, "Isn't she the one who sang the national anthem at the last inauguration?")