When designing your pop-ups, it is very important to make sure they look good on all device types: Desktop, Tablet and Mobile.
While Hello Bar does its best to adjust sizing automatically for each device, some pop-ups may look better on certain devices than others.
When you are in the Editor, you can toggle between each device type by clicking on the appropriate device type along the top menu. Then, you'll be able to see exactly what your pop-up will look like on each device.