@neutraluser I thought it's maybe a knife that one of them just dropped from hand and it's falling down?
generally, there are a few pictures like this here and there which really affects the air around the manga. And, as someone said too, the title sounds like a big red flag too,
but despite that, it does not seems that anything even remotely agressive or depressive would happen in the manga (as far as I seen so far) so despite ocassionally blood, and weapons appearing here and there, it just seems like a manga about a fictional russian lesbian couple doing lovey-dovey things.