>>9637593well in that pic they put the supporting brackets in backwards on both sides. i think the glass shelves are still long enough to be supported when it's assembled the wrong way, but when the cabinet gets moved they shake a little bit. they probably slid out when this person scooted the cabinet up next to the other one.
any case, i don't see any shattered glass there, so the shelves didn't detonate from weight or by falling to the floor. it was just user error not following the instructions.
>>9637309i put small pieces of foam window weather stripping on the edges of the mid shelf and that completely stopped the rattling. already had this stuff since i was using it around my shit house
https://www.menards.com/main/hardware/weather-stripping/1-2-x-1-4-x-17-foam-window-weather-strip/38326/p-1459185065514-c-3624.htm?tid=-7034130732226576890&ipos=52 