Hmm... how do I explain this (I'm bad at explaining things lol) >w<
It's because if the most important guest faces the Tokonoma, it's like the host is trying to show off its contents to them by making them look at it the whole time. Tokonoma have very strict etiquette surrounding them.
That is true! They are very soothing. Chash.itsu (tea rooms) are especially lovely. They have pretty gardens surrounding them. However, they also have very small entrances- which forces the guests to bow when entering.
Seasonality is very very important in Japan- which is why tokonoma have seasonal ikebana arrangements. Namagashi (a type of traditional sweet) also match the seasons- they are almost too pretty to eat (just google it and see what I mean) ;w;
There are actually 72 mini seasons in Japan
(see here) They aren't really observed today, but sometimes in kimono motifs (which also must match the season)they are. I have a trailing furisode kimono which I use for dance and it has motifs of butterflies, wisteria and cherry blossoms- perfect for Spring.
Eeeeek I started rambling again, whoops >o< But I hope you found this interesting! I like sharing my knowledge c: