When guests visit, we love having a Photos slideshow playing on our Mac. However, if guests show up with little or no advance notice (as they tend to do during the holiday season), you’ve got little (or no) time to go picture hunting. Happily, macOS Sierra lets you tell Siri to track down certain pictures for you. From that point, all it takes is a couple of clicks to get a slideshow rolling… click here to read the full tutorial on Macworld.com.