If you have an eagle eye, maybe you've noticed certain symbols on the Steam summer sale postcards. If you're a conspiracy theorist, you might even think they're teasing something. But what?
This image, posted on Reddit by rawberry1110, makes fun of where I'm sure your mind immediately goes now that we're talking about something a) involving Valve and b) conspiracy theories.
Didya guess correctly? Heh.
Valve's hidden symbols in the Summer Sale Cards - Solved [OC] [rawberry1110]