Ok in that case you should say 'the picture on the bottom left' it is 'bottom left' with no preposition if you put it in brackets within an article to refer to a picture. Backside is also colloquial and common. Yes, you seem to have it quite right
Why Is The Toilet Leaking Underneath at Robert Myers blog
And i can't think of how you'd use 'in the bottom of'
You're again quite right that we say 'in the bottom drawer', with it used in an adjectival way
'in the bottom of the drawer' perhaps if the drawer is very deep and you can feel things (socks, perhaps. What is the difference between in/at the bottom For instance.at the bottom of the sea or in the bottom of the sea However, bottom is definitely more polite than backside and is acceptable for ordinary conversation
Buttocks is a bit more sophisticated and is more suited to medical, legal or technical talk. I searched handwritings of letter f on youtube, and it's usually written as , pretty like the printing style Actually we were taught f in that style I’ve never heard anyone say that
I think most people would say the fridge has a freezer underneath
At could mean either inside or outside an item such as a fridge It depends entirely on what’s being referred to On would either refer to the outside of the fridge or mean on top of it. For ae, butt is common, idiomatic, and lower register than buttocks, bottom, or posterior
The last is little used, sounds old fashioned and stuffy