There are many misconceptions about language, so when exploring extremes like your creature, it helps to strip away all of the extra fluff and get down to what language does best: communicate information from one individual to another.
Consider a verbal description of the Mona Lisa. Information is encoded as sound waves emitted from one person's vocal box and processed by the other person's ear. One can break down this encoding into smaller symbols called phonemes, which are the smallest unit of speaking which a native speaker's ear can identify as a "thing." We can distinguish the difference between the sound of an "a" and an "o," so they are treated as different symbols. There are many sounds we cannot distinguish which are not phonems (see the famous infograph explaining what a modem can do with sounds!).
Symbols may also be handled at many levels. At one level, we may capture the words describing the Mona Lisa. At another level, we may capture the speaker's emotions regarding their experience with the painting.
Now do the same experiment using written text, like I am doing now. Once again, we have a set of symbols used to convey information. These symbols happen to be blocks of small square lights which can be on or off, in about a 20x30 block. There's 26 of these (52 if you count upper and lower case).
Once again, the symbols may be handled at many levels. At one level, we may simply write the words describing the Mona Lisa. At another level, we may try to capture the emotion we have, but its much harder with these text symbols. We may actually have to change the words to convey what we wish to say, and this is important. Its easy to presume that speech and written English are just the same, but that's only true at a very high level. At a deeper level, the conveyance of emotion is handled very differently, changing the words to match the medium.
Smell is a fascinating medium for communication. Unlike speech, which can clearly be said over a period of time, or written word, which can be written over a region of space, smell tends to diffuse outward. Its much harder to write "long" sentences using smell because the speed at which you can change the chemical environment around you is limited by diffusion, which is much slower than the deadening of sound waves or the fine edged regions of light and dark for written words.
Smell makes up for this disadvantage with an extraordinary array of symbols. We can actually process an extraordinary amount of information about the chemical world we live in. Bloodhounds can do it even better. How much information? The bloodhounds can devote a large portion of their brain to the processing of smells.
The trick is that smells can be intricate. You can do a remarkable amount of chemistry in your nose to identify the exact shape and makeup of molecules, and those molecules can be layered on top of eachother.
Smell is recognized as being very good at conveying emotion. Its why we use perfume. So, in this sense, we may find that the octopus species can actually describe the emotional je ne sais quoi about the Mona Lisa without much effort, even if they would have to strain to describe the scenery behind her. For many things, they may actually be better communicators than us!