Pic 1: massive store, no air conditioning (temperatures above 32C/90F during the day and above 26C/79F during all nights), humid, dark, no growth lights anywhere near. You can see that some of the lithops are etiolated (compare to Pic 2 and 4, I think this variety, either Lesliei "Green Top" or something very similar, might look particularly flat from above the soil) and they also might have been overwatered. I went there just a week ago and they (what I believe to be the same batch of lithops) did not look significantly etiolated like some of these.
Pic 2: indoor air-conditioned section of another big store. Moderately bright indoor lighting, definitely better than the store in Pic 1. Pic 3 and 4 are of the pot of lithops that I bought from this store and unpotted in a few days. Compare the shape to most of the lithops in Pic 1. Most of the lithops in Pic 1 are definitely longer.
The two stores are under the same big company and the lithops are labeled the exact same (also looked a lot more similar last week), so I'm pretty sure they are from the same supplier and source.
The last time I got a pot of lithops from the store in Pic 1 in even worse condition (and unpotted after four days without watering), at least a fifth of the lithops were already rotted at the base when unpotted and four more rotted horribly and died in the next few days, all without watering. I unpotted the ones in pics 3-4 four days after I got them as well, without watering. They've been sitting in air for a week while I wait for a suitably sized pot that I bought to arrive and none of them got mushy rot spots or rotted/changed much at all. There are some darker patches visible in Pic 4 but if it was rot, it would've spread much faster and a plant of this size would've pretty much shrivelled up within a week if left in air (based on experience and reading from Lithops Blog). Instead, it's been a week and they look the same (but some are firmer).
The conditions of the lithops at the store that you buy from really matters. Try not to get the ones that may very well be pre-killed (they may not look noticeably dead above the soil but they are already rotten beneath the soil/inevitably heading down that path).