How do I make the ImageLabel pop up?

I asked a question about decal popping up after a player wins a race. Well, I got that answered and tested it out. But it didn't pop up the decal and it didn't pop up the winner of the player either. This is the script with someone answering it:

local checkpoint1 = game.Workspace.Checkpoint1
local checkpoint2 = game.Workspace.Checkpoint2
local checkpoint3 = game.Workspace.Checkpoint3

local redLight = game.Workspace.StartLight.RedModel.LightBulb.PointLight
local yellowLight = game.Workspace.StartLight.YellowModel.LightBulb.PointLight
local greenLight = game.Workspace.StartLight.GreenModel.LightBulb.PointLight
local startBarrier = game.Workspace.StartBarrier

local raceInProgress = false

local lobbySpawn = game.Workspace.LobbySpawn
local trackSpawn = game.Workspace.TrackSpawn

local minimumPlayers = 2

function destroyCars()
    for _, object in pairs(game.Workspace:GetChildren()) do
        print(object.Name)
        if object.Name == "RaceCar" then
            print("This is the RC. Destroy it!")
            object:Destroy()
        end
    end
end

function createCars()
    for _, object in pairs(game.ServerStorage:GetChildren()) do
        local carCopy = object:Clone()
        carCopy.Parent = game.Workspace
        carCopy:MakeJoints()
    end 
end


function showVictoryMessage(playerName)
    local player = game.Players:FindFirstChild(playerName)
    createGui(player.PlayerGui)
    local screengui = player.PlayerGui.ScreenGui
    screengui.Frame.TextLabel.Text = playerName .. "has won!"
    for e = 1,0,0.05 do
            screengui.Frame.Transparency = e
        wait(0)
    end
    wait(1.5)
    for e = 0,1,0.05 do
            screengui.Frame.Transparency = e
        wait(0)
    end
end

function createGui(playerGui)
    local screengui = Instance.new("ScreenGui",playerGui)
    local frame = Instance.new("Frame",screengui).Size UDim2.new(1,0,0.1,0)
    local imageLabel = Instance.new("ImageLabel",frame).Size UDim2.new(1,0,0,0)
    wait()
    imageLabel.Size = UDim2.new(1,0,0,imageLabel.AbsoluteSize.X)--kind of a trick to get x and y the same
    imageLabel.Image = "rbxgameasset://Images/Background"
    local textLabel = Instance.new("TextLabel",frame).Size UDim2.new(0,frame.AbsoluteSize.X-imageLabel.AbsoluteSize.X,1,0)
    --Any Formatting to the TextLabel/Frame/ImageLabel would be done HERE
end


function checkpoint1hit(otherPart)
    print("Checkpoint 1")
    print(otherPart.Name)
    if otherPart ~= nil and otherPart.Parent ~= nil and otherPart.Parent:FindFirstChild("Humanoid") then
        print("Someone hit me!")
        if not checkpoint1:FindFirstChild(otherPart.Parent.Name) then
            local playerTag = Instance.new("StringValue")
            playerTag.Parent = checkpoint1
            playerTag.Name = otherPart.Parent.Name
        end

        if checkpoint3:FindFirstChild(otherPart.Parent.Name) and raceInProgress then
            print("Player wins!")
            raceInProgress = false
            showVictoryMessage(otherPart.Parent.Name)
        end
    end
end

function checkpoint2hit(otherPart)
    print("Checkpoint 2")
    print(otherPart.Name)
    if otherPart ~= nil and otherPart.Parent ~= nil and otherPart.Parent:FindFirstChild("Humanoid") then
        print("Someone hit me!")
        if not checkpoint2:FindFirstChild(otherPart.Parent.Name) and checkpoint1:FindFirstChild(otherPart.Parent.Name) then
            local playerTag = Instance.new("StringValue")
            playerTag.Parent = checkpoint2
            playerTag.Name = otherPart.Parent.Name
        end
    end
end

function checkpoint3hit(otherPart)
    print("Checkpoint 3")
    print(otherPart.Name)
    if otherPart ~= nil and otherPart.Parent ~= nil and otherPart.Parent:FindFirstChild("Humanoid") then
        print("Someone hit me!")
        if not checkpoint3:FindFirstChild(otherPart.Parent.Name) and checkpoint2:FindFirstChild(otherPart.Parent.Name) then
            local playerTag = Instance.new("StringValue")
            playerTag.Parent = checkpoint3
            playerTag.Name = otherPart.Parent.Name
        end
    end
end

checkpoint1.Touched:connect(checkpoint1hit)
checkpoint2.Touched:connect(checkpoint2hit)
checkpoint3.Touched:connect(checkpoint3hit)



function startLightCycle()
    redLight.Enabled = true

    wait(1)

    redLight.Enabled = false
    yellowLight.Enabled = true

    wait(1)

    yellowLight.Enabled = false
    greenLight.Enabled = true
end

function removeBarrier()
    startBarrier.Transparency = 1
    startBarrier.CanCollide = false
end

function resetLights()
    redLight.Enabled = false
    yellowLight.Enabled = false
    greenLight.Enabled = false
end

function resetBarrier()
    startBarrier.Transparency = .5
    startBarrier.CanCollide = true
end

function clearCheckpoint(checkpoint)
    for _, object in pairs(checkpoint:GetChildren()) do
        if object.Name ~= "TouchInterest" then
            object:Destroy()
        end
    end
end

function teleportPlayers(target)
    for _, player in pairs(game.Players:GetChildren()) do
            while player.Character == nil do
                wait()
            end
        local character = player.Character
        local torso = character:WaitForChild("Torso")
        torso.CFrame = target.CFrame
    end
end

wait(10)

while true do
    -- wait for enough players before we start the game
    while game.Players.NumPlayers < minimumPlayers do
        wait()
    end

    -- setup racetrack  
    -- turn off all lights
    resetLights()

    -- reset barrier
    resetBarrier()

    -- create all cars
    createCars()

    -- clear all checkpoints
    clearCheckpoint(checkpoint1)
    clearCheckpoint(checkpoint2)
    clearCheckpoint(checkpoint3)

    -- teleport all players to the racetrack
    teleportPlayers(trackSpawn)

    wait(5)

    -- start race
    -- start light cycle
    startLightCycle()

    -- remove barrier
    removeBarrier()

    raceInProgress = true

    -- wait for race to finish 
    while raceInProgress == true do
        wait()
    end

    wait(2)

    -- delete all cars
    destroyCars()

    wait(2)

    -- teleport all players to the lobby
    teleportPlayers(lobbySpawn)

    wait(10)
end