by meaning it is.
However, we know by now that Duolingo usually wants sentences in specific manner with specific grammatical rules regardless of the meaning.
For example, the sentence above says في المطبخ (in the kitchen) which is composed of a preposition and a noun (might call it as we ll a prepositional case). Your sentence, however, is genitive in construction where (kitchen window) are 2 nouns added together (X-of-Y kind of relation).
I can see that from the standpoint of a language that has declensions, one would see eg "kitchen window" as a genitive construction - window of kitchen. But as English has shed its cases (apart from a vestigial genitive - "'s"), English grammar views this construction as a noun (kitchen) modifying another noun (window), ie, taking on the role of an adjective. There are several grammar sites that deal with this, for instance: https://www.merriam-webster.com/words-at-play/nouns-that-look-like-adjectives
Actually, if this sentence above was put into some context, I would understand it as something "habitual" (like the simple present tense in English or maybe like the imperfect in Russian, or the simple present in Turkish).
Making the verb in present continuous in English would kind of "expressed" differently in Arabic, as Arabic only has one present tense. Something like إنني (innani) might be used before this sentence to give the impression of the action performed at the current time; It translates somewhat like (i am indeed).
On other occasions, the -ING or the continuous present tense is sometimes translated into Arabic using the "subject noun" or "verbal noun" (if i can call it so). It is a type of structure derived from verbs that have variety of uses, like giving names for crafts people, and generally speaking "naming the doer of the verb". This structure is common right now in usage in dialects right now, in a parallel meaning to the present cont. verb in English. In a nutshell, I am opening the window might be expressed as:
- إنني أفتحُ الشباك (innaní aftaHu al-šubbák); and also note that (innaní) can be compressed further to (inní) إنّي; Both are correct.
- أنا فاتحٌ الشباك (aná fátiHun al-šubbák); This one though feels and sounds like something out of a literature line, that sort of thing.
You say, "(like the simple present tense in English or maybe like the imperfect in Russian, or the simple present in Turkish)". I don't know about Turkish, but in Russian, aspects (perfective and imperfective) do not exist in the present tense, only in the past and the future.
I might help you in English, but in French, I can't. Check YouTube about the topic you want to learn more about in Arabic; There are some people (some Europeans) who post videos that help non-Arabs about some issues, like sounds of Arabic and other things.
Duolingo is not quite good for serious learners.
Unfortunately, not much. But I remember a channel by the name LearnArabicWithMaha (An Arab woman living in Canada I think) and another one by Mike Still (A British man who traveled the Gulf region). From there you might be able to follow and maybe YouTube can show more suggestions for you that would help.
Best of luck!
But everything needs a context, doesn't it? We wouldn't say "I'm opening the window" except in the context of actually opening the window. I think the problem lies in the fact that with the present continuous the context readily springs to mind, whereas with the simple present it takes a bit more thinking.