"Glancing" is a Sugar Surfing term. It's those quick looks at your CGM data while on the go. I glance often and it takes no more than a couple of seconds. The following tip might make this easier for you.
If you Sugar Surf using an iWatch, and assuming you have the latest updates for your iPhone and iWatch, you can put the BG and trend arrow icon at the bottom of most faces of your iWatch.
Press the screen until you get the customize button (above). Press customize. Then scroll using the watch stem until you find your Dexcom icon, then press the stem button to finalize your selection.
Happy Sugar Surfing!