Why my HUD is shown in ingame screen

[Core]

I downloaded XBOCT's Monitor from workshop. I got it working, but I wonder why it shows my HUD elements in the upper left corner of the "virtual" screen? What am I missing?

 

Edit. Added code from the monitor

---------------------------------------------------------------------------
-- Film Grain (Monitor) by Igor Katrich 28/02/20015
-- Email: igorbgz@outlook.com
---------------------------------------------------------------------------
Script.camera=""--entity "Camera"
Script.border_radius=2.0--float "Border Radius"
Script.inflate_rect=50.0--float "Inflate Rect"

function Script:Start()
	--Material
	self.material = Material:Load("Materials/Monitor/monitor.mat")
	self.entity:SetMaterial(self.material)
	--Context
	self.context = Context:GetCurrent()
	--Media
	self.defaultfont = self.context:GetFont()
	self.recellipse = Texture:Load("Materials/Monitor/Media/ellipse.tex")
	self.recblend = 0.0
	self.digitalfont = Font:Load("Materials/Monitor/Media/digital.ttf",30)
	self.context:SetFont(self.digitalfont)
	self.digitalfont:Release()
	--Buffer
    self.buffer = Buffer:Create(128,128,1,0);
    local color = Texture:Create(context:GetWidth(),context:GetHeight())
    self.buffer:SetColorTexture(color)
    self.buffer:Disable();
end

function Script:UpdateWorld()
    self.buffer:Enable()
	self.camera:Show()
    --world:Render()
	self.camera:Hide()
    self.buffer:Disable()

	self.context:SetBlendMode(Blend.Alpha)
	--Border
	self.context:SetColor(1,1,1,0.2)
	self.context:DrawRect(self.inflate_rect,self.inflate_rect,self.border_radius,self.context:GetHeight()-self.inflate_rect*2.0)
	self.context:DrawRect(self.context:GetWidth()-self.inflate_rect-self.border_radius,self.inflate_rect,self.border_radius,self.context:GetHeight()-self.inflate_rect*2.0)
	self.context:DrawRect(self.inflate_rect+self.border_radius,self.inflate_rect,self.context:GetWidth()-(self.inflate_rect*2.0)-self.border_radius*2.0,self.border_radius)
	self.context:DrawRect(self.inflate_rect+self.border_radius,self.context:GetHeight()-self.inflate_rect-self.border_radius,self.context:GetWidth()-(self.inflate_rect*2.0)-self.border_radius*2.0,self.border_radius)
	--Rec
	self.recblend = Math:Sin(Time:GetCurrent()*.4)-0.2
	self.context:SetColor(1,1,1,self.recblend)
	self.context:DrawImage(self.recellipse,self.context:GetWidth()-26-48-self.inflate_rect-self.border_radius-10,self.inflate_rect+self.border_radius+10,26,26)
	self.context:SetColor(1,1,1,0.5)
	--Text
	self.context:DrawText("REC",self.context:GetWidth()-45-self.inflate_rect-self.border_radius-10,self.inflate_rect+self.border_radius+10+1)
	self.context:DrawText(self.camera:GetKeyValue("name"),self.inflate_rect+self.border_radius+10,self.context:GetHeight()-self.inflate_rect-self.border_radius-10-25)
	self.context:SetBlendMode(Blend.Solid)
	
    Context:SetCurrent(context)
	
    local color = self.buffer:GetColorTexture()
    self.material:SetTexture(color,0)
end

function Script:Cleanup()
	self.digitalfont:Release()	
	self.defaultfont:Release()
end

I also have another question. If I want to show text, graphics etc on the wall, I just remove world:render() from the monitor script and use it to draw text etc.? What I mean to ask, is this the "right" way, or is there a better way to show text and graphics on wall, like a screen or maybe even a poster, sign etc.

Edited September 22, 2017 by Core
added question