That's because I have had 2 LGs for years (that I added PC fans to so they would be forced air incubators and more evenly heated, but I used them only for hatching). I hatched out somewhere around 1600-1700 Guinea Fowl keets plus a bunch of Silkie and Showgirl chicks, some Turkey poults and lots of Quail chicks in them, oh and a batch of Ringneck Pheasants too. So believe me, I know what the bottoms of LGs look like lol... because I have soaked, bleached and scrubbed mine clean after every hatch during the 4 yrs I used them for hatching (probably somewhere between 75-100 times, lol). I don't use them any more tho, too much temp fluctuation, and too much stress and hassle for me. Plus there's not enough capacity in them for large hatches, it's hard to get the RH up to 75-80% where I like it/and keep it for hatching keets, and I don't really like using them for hatching out bigger chicks and poults because they can get hurt from pecking at the fan (even tho it has small mesh hardware cloth covering it) or they can also get burnt by the heating element.I'm surprised though that you could identify my incubator just looking at the bottom it is a LG!
So yah, I know LGs well, I'm just not a fan of them... lol.