I dont know honestly. I wondered it myself when she moved in there. All I know is you hook up the TV, select cable and scan. It shows as analog numbers but its 720p (all stations)
I had a similar set-up about 10 years ago at an apartment building, about 50 units. It was the only service available available in the building and it was not included in the rent. You just plugged coax in the TV from the wall and you had cable, if you paid. Analog TV was still on the air and Lifetime, ch 3 on the Dish Network-fed system, ALWAYS had WCAX (CBS) analog in the background, no matter what you did. There was a weird FM-stereo-hiss effect, too, on the channel. All channels on the system were SD and mono audio, but the OTA broadcast interference did strange things to it. If you didn't have the service, it would just be static, with WCAX nearly clear as a bell on ch. 3. I assume the wiring in the building was getting the signal. You could see WPTZ (NBC) 5 but not really watchable. My neighbor only had channel 3, courtesy of this after I told her that it would work for just that channel.
I had an old set of rabbit ears, a decent indoor amplified antenna that I don't remember what it is, with a cable input in the back. I discovered that if you put the switch exactly halfway between "cable" and "antenna" it would work for both. It had no effect on the quality of the cable reception and only a small effect on the OTA reception. In fact, the WCAX-Lifetime situation improved (well, sorta - it meant Lifetime was clearer) because I could put the poles of the antenna all the way down in a manner that kinda put WCAX in a null. It could also blast over Lifetime enough that my ex wouldn't watch it if I left the antenna in the proper set-up. The UHF OTA channels (TBN W16AL 16 also fed by Dish Network, WVNY ABC 22, WETK PBS 33, WFFF Fox/WB 44, WGMU UPN 39, and WCFE PBS translator 46) would show up higher up on the dial. It was weird! The cable lineup stopped at channel 28 or so if memory serves, with WCAX, WPTZ, WVNY, WFFF and WETK being hte last channels in the lineup. I kept WCAX and WPTZ from the cable but programmed it to go to 67 for TBN, 73 for WVNY, 84 for WETK, 90-something for WGMU, 100 (or 99) for WFFF, and 105 or something for WCFE. The OTA channels were stereo, and the cable were only mono, so it was an upgrade. The OTA picture was better than the cable channels (except WGMU and WCFE which were bad - but bad is better than not there). Nothing was HD, but from 2005 to 2007, one would not expect it to be.
Often the cable channels would freeze for days at a time. It would take someone (often me because I was unfortunate enough to work closest to the landlord/cable office but not always) physically going there and not leaving until it was fixed. We did not have NESN or the former FSN New England on the cable. ESPN and ESPN2 were on there and there was no switch to the alternate if needed. Truly a terrible system. It has made me VERY leery of any such system until I started seeing Claude's posts.