Control Centre icon flashes intermittently on lock screen

i sometimes notice the control centre icon( I think, not sure what symbol it is but it looks like the control centre symbol) I see it flash under the top right of my lock screen. It comes down for a second then goes right back up, falls back down goes back so it kind of flashes periodically. It only happens sometimes and for sometime then it goes away. Just wondering what this means or if anyone has noticed this?