I think I saw this somewhere and I'm pretty sure it's mainly just pointing out pixel movement in relation to swinging on angles (for CSGO but it works in TF2 as well, especially if you do CSGO "entry-fragging" techniques ie: as sniper, placing your crosshair on the spawn door of process last as you peak from 1 before you can even see it so your rifle dot is already on the enemy player)
It basically goes like this:
If you are further away from an angle when you swing, assuming the enemy is in an unmoving position, the pixels of your in-game model will move slower across the screen making it "easier" to shoot you. This is why CSGO players stack up against the wall before they run out. However, keep in mind that the eyes of your model (what your screen shows) are not as wide as the model itself. If you are too close to a corner before peaking, your shoulder will show before what you see on the screen passes the wall, giving them a split second advantage (though this is a tiny bit nullified by peakers advantage).
Which is what the picture shows:
If Player A strafes to the side, he will see Player B a split second before Player B see him due to both what I wrote above and peakers advantage. The odds are in his favor.
If Player B strafes to the side, he will be moving "slower" making it "easier" for Player A to track and shoot him.
Conclusion:
If you are holding an angle, stay further back.
If you are peaking an angle, move closer before you swing.
*this is almost barely relevant: it assumes that whichever player is holding hits a perfect headshot on whichever player swings
**In TF2, this is even less relevant except in sniper v. sniper situations because: players movements are often faster than human reaction time in relation to holding angles and the sniper scoped movement speed is slow enough that both players (assuming both are scoped) will have a high enough reaction time/good enough tracking to shoot the other (also assuming both players are slemnish and can hit 100% hs) except at extreme distances.
In a comp. situation, the "best" way to take advantage of this is to swing close to an angle without being scoped, that way your pixels move the maximum speed across the screen for the enemy. Obviously, this is very situational and assumes the other players on the enemy team do not have a sentry, sticky traps, rocket spam angles, eyes, or hands.
Show Content
Just have your team distract the enemy sniper or change your angles. The best way to kill someone in any game is to shoot them when they aren't looking at you.