In a display assistant device, a display panel assembly has a plurality of first retention elements, and each first retention element is formed on a rear surface of the display panel assembly and adjacent to a respective first edge of the display panel assembly. A back cover is configured to hold the display panel assembly using a plurality of second retention elements. Each second retention element is arranged adjacent to a respective second edge of the back cover. When mated to each other, the first and second retention elements are configured to control an in-plane displacement of each second edge of the back cover in response to an impact of a force on the second edges, thereby limiting an out-of-plane displacement of each second edge of the back cover and protecting the first edges of the display panel assembly from falling apart from the second edges of the back cover.