It's generally recommended to wait before plugging in a mini-fridge that has been transported on its side, just like with larger fridges. The reason for this precaution is to allow the refrigerant to settle back into its proper position before turning on the appliance. Transporting a fridge on its side can cause the refrigerant to shift away from its intended location, potentially leading to issues when the fridge is powered up immediately after transport.
Refrigerant is a crucial component in the cooling process of the fridge, and if it doesn't circulate properly, it can affect the cooling efficiency and even damage the compressor. Allowing the fridge to rest upright for a few hours (at least 4 hours, but overnight is even better) gives the refrigerant enough time to settle back into the compressor and condenser where it needs to be.
So, whether it's a mini-fridge or a full-size refrigerator, it's a good practice to wait before plugging it in after it has been transported on its side to avoid potential cooling issues and prolong the life of the appliance. Always check the manufacturer's guidelines or user manual for specific instructions regarding transporting and setting up your mini-fridge.