Squid is a transparent fabric which enables you to see out during the day, but largely restricts people outside from being able to look in. So Squid helps you keep your privacy while still enjoying your view.
You can compare the effect of Squid on your window to that of frosted glass or a net curtain. Passers-by can't glare inside even though you're still letting lots of natural light in and can enjoy looking out. This is unlike plastic window-covering film, which blocks your natural light and you can't see through at all.
Squid also ensures you can enjoy being in a cosy cocoon in the evening. But it gets easier for people outside to see in as it gets darker outside, so it's best to close your curtains or blinds. The way Squid works is shown in the time lapse sequence.