Decent modern printers can handle overhangs fairly well. If the overhangs get too big you can use supports. If you want to get fancy there are filaments meant to be used only as supports in a multi-material print that dissolve in water so they don’t leave marks on the print.
FWIW I don’t think it was printed upside down. It would complicate things and would require more supports for no benefit.
Decent modern printers can handle overhangs fairly well. If the overhangs get too big you can use supports. If you want to get fancy there are filaments meant to be used only as supports in a multi-material print that dissolve in water so they don’t leave marks on the print.
FWIW I don’t think it was printed upside down. It would complicate things and would require more supports for no benefit.