Grand Theft Auto: San Andreas Easter Egg - Hidden Ammu-Nation

Yes this is true! You but remember you have to zoom in. Very good find!

strange... i cant find it...but i found something else... at the tatooparlor in las venturas if you do the same looking in the mirror with a sniper-rifle or camera you will see a hidden sex shop

Not sure if it's considered an easter egg. If I remember correctly, the game is set up as an exterior and interior universe. When you are outside, obviously the outside universe is loaded up. The internal parts of the buildings are loaded on the fly as the Interior Universe. So the Clothing Place and the Ammo Nation are probably located back to back on the Interior Universe layout. Zooming the camera in most likely excludes the wall facing that barrier and so you see the "hidden" Ammo Nation (more of a glitch). For sake of speed the game mechanics are divided like this so when you are running around the city, you aren't really loading all of the interiors of the buildings as well. So, maybe not an easter egg but more like a glimpse into how the internal mechanics work for your favorite game.

If you have CrazyTrainer +151, activate the Jetpack mode (it will make you fly and allow you to pass through any surface that you cannot pass when this mode is not activated) and fly through that mirror. You will find yourself in an empty void. Don't disable the Jetpack mode! You will see that actually what Darianknight said before is true. There is the interior of that ammu-nation that he mentioned there. Fly inside that ammu-nation and stand somewhere near the exit door. Then you can disable Jetpack mode. Walk outside the ammu-nation, and then something funny will happen. You will find yourself in San Fierro outside of a local ammu-nation in Ocean Flats. But instead of writing "Ocean Flats" in the left-lower corner of the screen, it will write "Jefferson" first. Only after it, it will write "Ocean Flats". Then enter in that ammu-nation again. Activate the Jetpack mode again. Fly out of the wall that is left to you, and get back to that sub-urban shop. Get out of that shop, and then the same thing will happen. It will write "Ocean Flats" instead of "Jefferson" first, and after that it will write "Jefferson".