Why won't my image labels show the picture?

Your Problem

The yields on lines 32 - 50 are too small for the images to load. You request the image, then change it to the next one before it gets a chance to load.

What You Need To Do

You need to use the Preload function of the ContentProvider service. The Preload function loads assets before they're used, so that once they're used they will have already been loaded.

Notes About Preload

A very important note is that the content is loaded asynchronously, meaning that the code does not wait for the assets to load before continuing to read the rest of the script. Preload does, however, queue the requests.. meaning that no matter what, eventually, the asset will be loaded.

Due to Preload loading asynchronously, you need to take advantage of the RequestQueueSize property of ContentProvider service. This property contains the number of assets that are queued to load. To manipulate this to your uses, you need to use a while loop to wait until this property's value is 0.

Code

--ContentProvider service
local content = game:GetService('ContentProvider')

--Put your images into a table
local images = {
	"http://www.roblox.com/asset/?id=265429534",
	"http://www.roblox.com/asset/?id=265429621",
	"http://www.roblox.com/asset/?id=265429697",
	"http://www.roblox.com/asset/?id=265429797",
	"http://www.roblox.com/asset/?id=265429863",
	"http://www.roblox.com/asset/?id=265429880",
	"http://www.roblox.com/asset/?id=265429916",
	"http://www.roblox.com/asset/?id=265429966",
	"http://www.roblox.com/asset/?id=265430040",
	"http://www.roblox.com/asset/?id=265430128"
}

--Load the images, from the table
for _,v in next,images do
	content:Preload(v)
end

--Your Code
script.Parent:RemoveDefaultLoadingScreen()

local screen = Instance.new("ScreenGui")
screen.Parent = game.Players.LocalPlayer:WaitForChild("PlayerGui")

local frame = Instance.new("Frame")
frame.Parent = screen
frame.Size = UDim2.new(1,0,1,0)
frame.BackgroundColor3 = Color3.new(255,255,255)
frame.Transparency = 0

local textlabel = Instance.new("TextLabel")
textlabel.Parent = screen
textlabel.BackgroundColor3 = Color3.new(255,255,255)
textlabel.BackgroundTransparency = 1
textlabel.Position = UDim2.new(.4,0,0.65,0)
textlabel.Size = UDim2.new(0.25,0,0.1,0)
textlabel.Font = "Legacy"
textlabel.FontSize = "Size24"
textlabel.Text = "Im all fired up!"
textlabel.TextColor3 = Color3.new(0,0,255)
textlabel.TextScaled = true
textlabel.TextWrapped = true
textlabel.TextXAlignment = "Center"
textlabel.TextYAlignment = "Center"

local imagelabel = Instance.new("ImageLabel") 
imagelabel.Parent = frame
imagelabel.Size = UDim2.new(0.25,0,0.5,0)
imagelabel.ZIndex = 2
imagelabel.Position = UDim2.new(0.4,0,0.1,0)
--Iterate through table
for i,v in ipairs(images) do --ipairs iterates in order
	imagelabel.Image = v
end

local count = 0
while game.ContentProvider.RequestQueueSize > 0  do
    textlabel.Text = "I'm all fired up!" .. string.rep(".",count)
    count = (count + 1) % 4
    wait(10) 
end

screen.Parent = nil