On screen after turning on camera have a brachet around a hand - what does that mean - canon powershot sx 600 hs

It's a warning that any vibration or harsh movement on the camera will prevent you from shooting a clear picture. You can still take a picture sure but it might come out blurry or out of focus, not enough light for the camera to lock on proper focusing. It also means it's better if you use a tripod to prevent camera shake or movement.