Translation:The chair that we bought is too tall.
Does this mean that the seat of the chair is too far from the floor, or that the back of the chair is too high? Or can the Czech here mean either?
It is unspecific. Can mean almost anything. The first thing I imagine is a chair which has the seat to high, but it can be also too tall to fit somewhere.
BTW, I think I have never used this "již" in my life. Not spoken, not written. Just to weird, old, bookish, formal, I don§t know what is the right word, but I would have to thing long to use the correct declination. Probably I would have to refer to a Czech grammar handbook.