I think the problem is that the OP was not clear enough in his question or context, likely due to ignorance of the terminologies given from the "contractor".
From that chart, I surmise that the context the contractor is referring to is very very large "jumbo-tron" type display walls, where the image is created by vast amounts of somewhat large LEDs in panels, meant to be seen by large crowds from a distance; like this:
Pixelation becomes very apparent when close up and this technology is typically not suited for SCADA system monitors and HMIs.
This is versus a number of LCD screens arrayed to coordinate into a single image, like this:
Also not typically used for SCADA / HMI monitor applications, but it has been done for large facilities where people want a "big picture" view.
For SINGLE monitors / HMI displays, the terminologies are different.
"LCD Display" = LCD displays are "transmissive" in that the LCD elements BLOCK varying amounts of light with the liquid crystal, and that light is PRODUCED by something else. The original older LCD technology used CCFL (cold cathode fluorescent lamps) for the back lighting. Almost NO (high quality) industrial LCD monitors still use this technology, because as time wears on the CCFLs get dimmer and nobody likes that.
"LED Display" = is actually still an LCD display, but one that uses LEDs for the backlighting of the LCD elements. MOST industrial displays / HMIs now use this technology. Long life, low power use, vibration resistant etc. etc.
"Direct LED Displays" = LCD with LED backlighting, but each LCD element has an individual LED backlight directly behind it, as opposed to the original design that has the LEDs only on the sides, reflecting in, then back out through the LCD elements. Direct LED technology gives better contrast control, but costs a lot more.
OLED Displays = latest technology. They use individual "emmisive" LEDs to create the image, so no backlighting is needed at all. They consume less power so are better for battery powered things like tablets and phones, but the cost for large displays, like what you might see in a SCADA system, can be prohibitive. Only a few off-brand HMI manufacturers are using OLED technology for
non-mobile HMIs, at least so far. But when they are battery powered, the lower power consumption overcomes the cost differential compared to the cost of increasing battery capacity or sacrificing up-time.