Strange LED

It appears to be a small surface mount LED with a moulded lens added by the panel maker.

Yes, it's an LCD TV panel - the SM LED has a moulded lens fitted over it.

You can (and should) buy the ready assembled strips for replacement purposes, these are easily and cheaply available from China (and Ebay etc.) - trying to replace the individual LED's means you have to VERY, VERY accurately refit the moulded lenses, and even a small misalignment produces visible patches on the TV picture.

As a further point, LG (in particular) made vast numbers of sub-standard LCD panels (and as well as using them for their own sets) sold them to many other manufacturers, such as Samsung. Basically they 'cost improved' the panels by reducing the number of LED's fitted, as a result the LED's are driven too hard, over heat and burn out, even melting the moulded lenses off them.

Now am pissed off. Searching for backlight LEDs, now they call the same name to the rear 'ambient' light behind TVs. Some genius used the same term; and the sheep follow making a mess on terminology.
Those backlight LED emitters, if need for repair, are available :

----> https://www.ebay.com/itm/274163774233

The 2835 (or 3528 by some manufacturers) are very common, bright and cheap - just what is needed for the array behind a TV. Unfortunately, they need to be "binned" so all the LEDs on one TV have the same color of white emitted. Otherwise, you'll get something like this off-spec screen replacement with one weird color patch of yellow in a field of white.

You'll say it doesn't bother you but your eye will jump to it whenever you look at the display. The photo doesn't do it justice - much more noticeable in real life.

Look at the datasheets of Osram, or Samsung who make these, they typically have about two dozen "bins" because your eye is so sensitive and can pick it up.