I am asked to removed the arrow of the popover view.
Sure thing, and there is plenty of call for this, specifically when the popover is large enough and the point at where the arrow would point would be obscured.
There's no usability drawback whatsoever.
[pop presentPopoverFromBarButtonItem:_toolbarBtnImage2
permittedArrowDirections:0 // <- pass in zero for no arrows
animated:YES];