Pretty much all LCD displays have been using LED backlighting for quite a while now, and LEDs do not have a warmup period.  Older LCD displays that used CFL backlights could indeed take some time to warm up before reaching optimum contrast, color reproduction, etc.  I'm not sure how to account for what you're seeing.  I suppose it could be some other aspect of the display electronics, but it would not be a literal "warmup" period.

Just wondering if you found anything out regarding this?

I am having the exact same experience on a new Alienware M17 R3, your post describes my experience exactly and my concern is that there's an underlying hardware issue causing this that may fail later.

@ejn63  the data connection of the laptop screen is organised to refresh the screen panel in square zones or tiles. 

Consumer LCD screens are made from two sheets of glass coated with a very thin layer of a conductive material -- one front, one back.  They are in no way made from "individual tiles". It doesn't matter if it's a 4" screen in a phone or an 80" screen on a television set -- the glass is two pieces the size of the screen.  These are surrounding a layer of liquid crystal material.  That may become more sluggish at very low temperature, but well outside of normal operating temperatures.  They are also surrounded on the edges by solder traces that may also be subject to temperature expansion and contraction.  Under normal circumstances, you should not see large fluctuations in image quality - certainly not within the design parameters of the screen's operating temperature, which is usually from well below zero C to about 80 C.

Though the post above is in error as to how an LCD functions, if the panel is showing fluctuations and the system is under warranty, ask for a panel replacement.

Hi @ejn63 there are many articles on the internet. Please share an update. Thank you. 

I'd like to see a scientific reference for that claim.

Hi @Whokam  @Lihp8270  laptop systems require to organise their operating system when switched on, see Task Manager activity. This does not last long, but ideally users should wait for a low activity level before using the laptop. However, laptop's screen panel has almost instant availability, and there is no warm-up or flicker.

The screen panel is made from tiles, so it you see a large square area flickering, the screen panel might have a manufacturing fault that cannot be fixed. Dell recommends running the LCD built-in self-test (BIST) on a laptop. If a problem is revealed during BIST, use an external camera to record and provide evidence, then raise a fault ticket so that Dell Product Support can fix this problem. 

When the new system is delivered, BIST should always be part of the user's check and acceptance process, within the first 30 days from invoice date. 

If the screen flickers when the lid is moved, a cable reseat may be required. 

If there are, by all means, please supply the link.  Every LCD matrix I've ever seen is a line device, not "tile" device, which is why one common mode of failure is for a single line of transistors to fail. That usually happens when one row of transistors sees a circuit fault at the edge connector. The image is sent across the width of the screen -- not in "zones" or "tiles" -- at least not in any commonly used engineering of LCDs I've seen.

It is possible for LCDs to go dark at the edges, where they're subject to higher temperatures, but I've never seen an LCD engineered into "tiles".  Even light bleed generally results from physical effects at the edges of the screens -- and doesn't extend very far into the screen itself.  

Hi @ejn63  thank you for the invitation. I know the answer, so decline your invitation. Thank you.