Instead of making your _arrayOfImages an array of image views, make it an array of images, and then do this in viewForRow:forComponent:reusingView:,
-(UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view {
UIImageView *iv = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 40, 40)];
iv.image = _arrayOfImages[row];
return iv;
}