@nikorocksun Oh no worries. Posting video completely fine too, perhaps I just couldn't exactly understand what you were mainly asking so I kept watching the video trying to see which stores have that mass population so I can look for it, but there wasn't any
Speaking of which, you can try A New GTA mod from eshenk. It's not spesifically for stores but the ped density is massively increased in his mods. GTA has a hardcoded limit to ambient ped density, so the mods you see here and youtube claiming they increased the ped density are either fake or wrong. You can't put more peds on streets by editing gameconfig or increasing ped density above 1 in settings.xml .
There are 2 ways regarding to this although none of them are actually increasing the ped density in how you think.
1st one is editing popcycle.dat and removing fishes and birds from the ped pool. This will leave more space for human peds to spawn in those areas, but then, there won't be any fishes in sea or seagulls or any bird, cat, dog at all.
The 2nd way is editing the scenarios, which is the way eshenk did with his amazing mod. Scenario peds are different than ambient peds. While ambient peds are full on autonomous AI, scenario peds executing the tasks assigned to them in scenario .ymt files. Eshenk gave them task to spawn at various places and walk on designated route. For instance, they spawn at Hollywood Walk of Fame and walk all the way to Beach. There are spawns in between as well to prevent popins and outs.
Aside from those 2, there isn't any other way to increase ped density.
The reflections on ground are done with ENB as well. I think it had a seperated column for it. It's not a raytracing but it mimics the raytracing. Call it like how iPhone's software+hardware Dynamic Island is mimiced with only a software in Android. Not same, but looks similar.
Since the light amount increases on streets and buildings, the puddles on the ground having more light to reflect, resulting in with a more exotic look. It looked like in your screenshot the ENB reflection is disabled or too subtle. It's either because the reflection quality is low or there isn't much light to reflect. When you increase the emissives though they will look very vibrant.
Long story short, these videos are not exactly mods. The values are balanced so people don't complain about the performance and the differences at day or night. So some people increasing some values way beyond the limits for different times and weathers of day, then trying to sell those. But they are something anyone can do by spending some time to edit and fine tune the values to their liking
I can add, you can try 5Real. That's a mod with many newly added buildings and lights. It's really good and devs worked a lot on it, though a bit too performance heavy. I removed the road textures it adds and using the NVE's roads instead.
Sorry for a long post by the by, tried to explain everything so you can know how to get the exact look you want
