For designers working on looks for the Met Gala, preparation usually begins months in advance. Makeup and hairstylists start working on clients in the early hours of the day of the event.

And then — snap. Their meticulous workfloods social media channels. There was Rihanna’s bejeweled white Maison Margiela “Pope-tastic” ensemble, Ariana Grande’s strapless Vera Wang Sistine Chapel ball gown. Fire emojis and comments like “yas” abound.

In years past, posting on social media was banned after the red carpet. But celebrities have begun to lift the veil on an exclusive event that most people are unlikely to ever attend. (Tickets cost $30,000 apiece plus the personal approval of Anna Wintour.)

So if you want to really get close, look no further than the social feeds of the guests.

Preparations for the Met Gala

Nicki Minaj said it took her five hours to get ready. Olivia Munn said she had been getting ready since 10:30 a.m. and was sewn into her dress en route to the museum. Katy Perry’s outfit was so large that to travel to the Met, she needed a convertible to accommodate her wings (yes, wings).

Here’s a look at the extensive preparations, from the feeds of attendees:

First Look

Call it the Beyoncé Effect. For years, she has been sharing her looks on Instagram before emerging in the public eye, controlling her image and narrative before photographers have the opportunity. Many have followed her lead, giving fans a sneak peak.

Perhaps no celebrity guest put as much planning into her social accounts as Miley Cyrus. As she arrived on the red carpet, a video of Ms. Cyrus in her Met Gala get-up was tweeted, her Instagram account became a grid with photos in her outfit forming a cross, and she had updated her Facebook profile with an album of her look.

Inside the Met Gala … and the After-Parties

What happens inside the Met Gala is supposed to remain a mystery, or at least offline. But every year, a few photos, videos and rumors from the event and its after-parties manage to find their way onto Instagram, Snapchat and Twitter.

There’s no big bathroom selfie this year (well, yet.) But Eva Chen managed to snag this group shot while still in the museum. She was one of this year’s biggest rule breakers, briefly going live on Instagram to stream Madonna’s performance at the gala and sharing multiple images from inside the party on her Instagram story. Catch it while it’s still up.

For more behind the scenes coverage, follow @nytimesfashion on Instagram.