Because it only shows the arrow when your BG is changing quickly, not slowly. Which hardly ever happens considering you're a very well controlled T2 and not the T1 jumping from the 2's to the high teens for who this device originally was intended.
I wager at some point between 19:19 and 20:20 the arrow has pointed down, but you weren't looking at that time. By 20:20, when you scanned, it must have been rather stable.
I never look at the arrows, for me, they're utterly useless, being rather stable. Instead, I scan, which shows the current number and the graph for the past 8 hours, and then press the little arrow at the top left to make it show the last 24 hours, making the rises and falls more pronounced.
On that graph I can easily see if I'm rising or dropping, and much clearer than with those arrows.
Take my current graph for instance (and keep in mind it reads lower than blood for me).
Had something to eat at 3:30 and took a little less insulin than it turned out I needed because I'd been lower than anticipated all day.
Had two carb heavy beers starting at 5:30, dosed normally for them, rose up to over 7 with a fingerprick, shown as 6 on the graph.
Figured I should have added a correction for the food before and took a small correction at around 7.
Which wasn't needed after all, judging from the steep drop, I had just been impatient.
Dropped me back to close to hypo when I was about to eat, a low carb meal I usually need a couple of units for, but didn't take them considering I was on the low side already.
To bring me to my point:
Right now, I can clearly see I'm rising from the food in my graph, even though the arrow stays horizontal because it's a slow rise.
The graph is much more informative than looking at the logged scan moments, that log is the one feature of Librelink I never use, except to get me to the 24 hour graphs with notes when tapping the page.
