It's the darkest part of the year. The sun's rising at 7:00 and going down around 4:30 and a lot of the time you wind up riding in the dark. And I get it, you feel kind of invisible: somehow the dark in winter often feels thicker and darker, like your headlights just aren't cutting through it the way they do in the summer.
That is still absolutely no reason to do this.
Ultrabright lights are bad enough. Look at how blinding this guy is. I had my left hand up to try and shield my eyes, which isn't a great thing to have to do in winter when you want both hands on the handlebars to be prepared for snow or other bad road conditions. But then you add the strobing effect and it's so much worse. Hard to pay attention to much else around you with that flashing light forcing your attention, for one thing. But also, people who do this think it makes them "more visible." It actually doesn't.
Watch this guy. You can see he's there for quite a long time, from a couple of blocks away in fact. But you can't really tell how far away he is, can you? And one effect of the strobing light is that he appears to be a fairly long way away for quite a while, until suddenly you recalibrate your perception and he's right there.
That's how drivers perceive it too. They can't tell exactly where you are, or how fast you're going. Not exactly safe.
Add to that the reports that these flashing lights have been known to affect people with seizure disorders and migraines, and now you're just being a jerk.
Don't strobe. Especially not at this brightness. One of those little blinky turtle lights you get for $4 at the bike shop? Okay. But 400+ freaking lumens? GTFO. I'm still blinking away retinal afterimages.