A student who encounters душе for the first time here and learns its meaning on hover will inevitably think that the same word translatess both "soul" and "shower." Somehow DL needs to indicate that two separate words, one masculie and one feminine, happen to have the same form in the prepositional case. Indeed,, since it is not pertinent here, they should omit the definition "shower" and reserve it for a more appropriate context.
Additionally, they are pronouncing "soul" here as "shower" with the stress in the bubbles. IIUC "shower" is «ду́ше» and "soul" is «душе́».
This is similar to сто́ит / стои́т which Duolingo also often stresses incorrectly. I'm surprised this is such a long-standing issue that they can't disambiguate heteronyms, this isnt a Russian only problem.
This subject matter should be in the spiritual skill and not in the body skill. The spiritual skill has words like religion, ghosts, and fate - beliefs and opinions like the concept of the soul. But the body skill is focused on words like fingers, legs, and headaches. It seems out of place here.
But remember, all your humble students know about this word is what we learned on hover. We don't know there is another similar word with the second meaning, so to us it is just as reasonable to use "shower" as it is to use "soul." All those helpful hints depend on knowing that there are two different words, one masculine and one feminine. This is where DL needs to help us avoid such confusión.
Look under the right-most column, "prepositional". It's not that there's specific сво- endings, they use the possessive pronoun endings according to gender and case: https://www.flickr.com/photos/30830242@N07/9105888519/
The short answer is that you learn the gender along with the word.
The long answer is that most (by no means all, but most) nouns in Russian give you a lot of clues as to whether they are masculine or feminine or neuter.
Nouns that refer to a person are generally the gender of that person regardless of spelling, so for example бабушка is feminine and дедушка is masculine, because grandmother is feminine and grandfather is masculine, regardless of spelling.
Nouns that don't have an inherent gender you can usually tell because of the spelling. Душ ends in a consonant; nouns that end in consonants or in й are likely masculine. Душа ends in а; nouns that end in а or я are usually feminine. Письмо ends in о; nouns that end in о or е are typically neuter. Nouns that end in ь can be either feminine or masculine and must be learned.
There are exceptions to these rules; besides the ones for obviously gendered nouns, the most common one I can think of is that coffee кофе is masculine, not neuter. (Although even native speakers sometimes get that wrong.) But for the most part, Russian is pretty consistent and helpful in this regard, and if you follow the rules above, you will guess correctly most of the time.
I'm pretty sure there are grammar notes on this in the pages of the course, and recommend that you check them out; the Russian course is imo one of the best on Duolingo regarding the grammar notes.
Both вы думаете о своей душе and ты думаешь о своей душе should be accepted, especially on a course that's been around as long as this one; if you wrote using the ty form and got it marked wrong, it may not have accepted the ty form but it's honestly considerably more likely that you made a spelling error.
Oh, and свой is a reflexive possessive pronoun. It sounds more natural in Russian in this context. It means 'one's own'.
This is pathetic. It took me 10 minutes to get the pronunciation correct. I finally got tired of it and recorded Google Translate's pronunciation at both slow and fast, you would not accept that either. Then I tried 2 more translate services and recorded the, and played them, you would not accept them either. Your audio recognition on this is pathetic,
As far I know, Russian did some of the most prominent researchs and experiments of the metaphysical role since the XIX century at least, from Blavatsky to soviet scientists. I can't remember exactly the name but they figure out the aura by its electromagnetics properties, and some use them for really accurated medical diagnosis.