Like, are they bright enough to illuminate a room as much as a small TV? A cell phone on half brightness? It’s hard to judge the brightness based on the photos in the store, and I haven’t been able to find pictures or videos on youtube of the strip or square in the dark. Actually there’s surprisingly little internetstuff about BlinkStick’s stuff in general.
EDIT: Managed to miss this thread which kinda implies that it’s as bright as a TV.
Square and Strip are surprisingly very bright. When all LEDs are lit up, they produce about 17000 microcandela. Looking for a way to compare this to some actual hardware for you 
If you have completely dark room, these devices will easily illuminate the whole room and you would easily see everything around. They are directional, so you have to bare this in mind.
Yep, very bright. We´re using it in our office and must put it somewhere out of call center agents sight, so it is not directly on the top of the soundproofing wall.
Take a look at the photo here:
Just got my flex in the mail today. With the blinkstick set to only control 8 so they didn’t get limited, I think the best way to describe them is “blinding”. Holy crap. 
Came up with a technique to use