In Мой Пушкин by Marina Tsvetaeva, we have
сидела под роялем, затылком в уровень кадке с филодендроном
If we had "затылком в уровень с филодендроном", I would understand as "the neck at the level of the philodendron", but I don't know what to do with "кадке". I saw that there exists the word кадка, but I cannot parse "в уровень кадке с" in a grammatical way that makes sense (кадке could only be a dative or a prepositional while уровень is an accusative).