Your obnoxious little brother loves to outwit you.
You are determined and ready to teach your brother a lesson.
But can you ?
The answer is:
The first row of the provided image contains many pixels that are just off from white; that is, some have RGB values like (254,255,254) instead of (255,255,255).
Reading across the first 480 pixels' values, we can extract 1440 bits. (For each pixel, use the least significant bit of its red value, then green value, then blue value. So (254,255,254)=> 010.)
Dividing these 1440 bits into groups of 8, this gives 180 bytes, each of which is a printable character in ASCII, giving this:
The characters in that string aren't just printable; they're all letters and numbers. The string ends in an '=' sign; this heavily suggests Base64 encoding.
Decrypting the Base64 string gives:
I am self repeating. I was in existence since time immemorial but named in 1975. I am iterative and infinitely detailed. Who am I ?
Self-repeating, iterative, infinitely detailed designs are often called fractals. While fractal designs or near-fractal designs occur frequently in nature (in existence since time immemorial) and while mathematicians have studied these designs since long before 1975, it was only in 1975 that Benoit Mandelbrot coined the word fractal.
A far-fetched answer:
The symbol is 'infinity'. A google search of the symbol returns 'infinity focus'. Infinity focus is the state where a lens or other optical system forms an image of an object an infinite distance away. In this case the light rays travel to/from the object parallel to each other. This is for the 'visual' tag of the puzzle. The next one is the 'computer-puzzle'. The same symbol (although a bit modified) is used a logo for the Microsoft's Visual Studio. So, my conclusion is that the little brother boasts that he is learning parallel programming using Visual Studio.