The photo was taken by a pilot of a French Air Force Mirage 2000-5F pilot during a training intercept on a Belgian Air Force F-16AM.
Most probably, the Belgian “Viper” did not react at all to the simulated attack by the French fighter jet belonging to the Groupe de Chasse 1/2 Cigognes (that posted the image on their Facebook page): every now and then, NATO and allied air forces take the opportunity to practice interception on military traffic transiting through their airspace of responsibility that agrees to be intercepted for training purposes.
Related link: Watch: C-130 Super Hercules Goes Inverted at Farnborough 2018
Such close encounters terminate with the identification of the “zombie” and no simulated dogfight takes place, as the “enemy” plane is not involved in any exercise but is simply flying as a General Air Traffic.
The image reminded us is the famous scene of Top Gun . when Maverick turns its F-14 Tomcat upside down to give the finger to a Soviet Mig pilot and the subsequent talk with “Charlie”:
C: “So, where exactly were you?”
M: “We started up on his six when he pulled through the clouds. I went above him.”
C: “If you were directly above him, how could you see him?”
M: “Because I was inverted.”