Windows Vista SideShow
Windows Vista SideShow technology enables laptop manufacturers to include a secondary or auxiliary display in future laptop designs. This display can be used to easily view the critical information you need, whether the laptop is on, off, or in sleep mode. The convenience provided by these auxiliary displays will save time and battery life by allowing you to quickly view meeting schedules, phone numbers, addresses, and recent e-mail messages without having to start up your laptop.
It would be interesting to see SideShow capable bags/outfits that a store manager/associate could use on the store floor. This would enable the store manager to be in touch with alerts and critical messages while on the store floor.
An interesting concept from Eleksen via Engadget: https://www.engadget.com/2007/01/08/eleksen-slaps-sideshow-on-a-messenger-bag/
From PC World: https://blogs.pcworld.com/staffblog/archives/003479.html
Details from Eleksen: https://www.eleksen.com/assets/PDFs/datasheets/ds_sideshow.pdf