About three minutes before the film ends, Cherry has been dancing to the music of a vinyl record for a considerable time when the music begins to repeatedly skip. The scene cuts to the record on the turntable, where the stylus is seen skipping on a groove on the very outside edge of the record, which is the very start of it and its music.
In the opening scene, Deena is using Hey Siri on her iPhone to send texts and create reminders. Her phone is shown and it is not plugged in. Hey Siri requires an external power source to use and there is no power source shown connected to her phone.