For avgeeks it’s simple to understand but many people asked me about this and other pics so let me explain to non avgeeks out there!

Let me show you the source.

This is the Real Picture

Then,

He cropped that selfie & airplane and pasted it on picture of clouds. (Yes he added effects on airplane fuselage which makes it looks like the plane is really on air)

As simple as that!
Thanks to photoshop

Now,
Let’s talk about some simple facts. (For non Aviation people)

1. That’s Boeing 737-800 as far as I know.
2. That guy won’t be able to breath at that level (assuming more then 10,000ft)
3. The plane cruise fast enough that it couldn’t not be even possible for him to take even his hand out. (I tried taking my hand out during my initial pilot training on  small C172 and it required lot of efforts to keep my hand stable at 100 knots) – even you might have tried pulling your hand out from your car, right?
4. This is possible on smaller airplane ( one  of my friend did it on DA42) because those planes fly really way too slow then these jets.
5. Being pressurized plane (b737), it’s really hard to open doors or windows at that level.

Let me show you one more fake selfie.

Check it out! If you can see terminal on that fuselage

As commented, to see what it would have been like if the plane really was flying at altitude like in the photo, refer to British Airways Flight 5390 where the cockpit window blew out and sucked the pilot out of the cockpit, but through skill, fate and luck, someone was able to hold on to the captain’s legs while the copilot performed an emergency landing.