Earlier quoted context omitted.
That link itself is a dark pattern. It tries to get you to sign into Google; you can't see the photos otherwise.
If it were truly the case that you couldn't see it without signing in, that would not be a dark pattern - there's nothing misleading about that, it's just a policy you don't like. using the buzzword of the moment to criticize something you don't like, without considering whether it really applies, is how phrases lose all their meaning. (of course, that's not true here and you don't have to sign in)
I'm thinking of Dropbox, which does this when you try to access a link that someone shared with you by email https://a3nm.net/share/2016-12-07_548165.png
This is a dark pattern because it's trying to make me believe that I should create an account when obviously I just want to get the file that my friend sent me. The link to download the file directly is at the bottom of the message.