This is not a new feature per se, more like an improvement of the current system. Right now, if you want to paint something on the screen pixel-by-pixel, you use 1x1 frames. This does work, but it can cause the framerate to drop, effectively crashing the game or ruining the experience.
My proposal is to introduce a Canvas GUI object which has a method for setting pixel colors and their opacities in specific positions. As mentioned before, this won’t introduce any security or safety issues, as the functionality already exists using frames. The only thing that would change is decreasing lag associated with it. Doing so could allow for 2D animations, special effects, or even mini videos (like tutorials) being displayed in the game without the associated lag.
Something like this:
local canvas = Instance.new(“Canvas”, game.StarterGui.MyGui)
canvas.Size = UDim2.new(0, 150, 0, 150)
canvas.ZIndex = 10
canvas:SetPixel(x, y, Color3.new(r, g, b), opacity)
In summary, the advantage to this is that it would allow developers to draw pixels to the screen without the extra lag caused by frames. There is not really a disadvantage considering you can achieve this exact functionality with 1x1 frames.