How does the author use imagery in the novel, The Verifiers?

Example of Imagery:

“The phone is locked, but app notifications show up on the lock screen. I scroll for a few minutes without seeing any bloodied daggers, as Inspector Yuan would say, but there are several hundred more to get through, and I can already tell I’ll have to go slow to make sure I don’t miss anything relevant amid the flotsam of Facebook and Instagram and Twitter updates. (One of the side effects of this hyper state, apparently, is that I start mixing my metaphors like a psychotic bartender)” (194).