Well, I just hit a milestone in my project and looked at the RAM usage. It was a bit high for what it does (around 90mb). Also keeping it low for Android.
Therefore, I started profiling. I found out, that once the RenderWindow is being allocated, 60 of these are just gone.
To be exact:
rendering_window = (std::make_unique<sf::RenderWindow>(window_mode, title_bar_text));
There is not much I could provide you with, the profiler's graph just shows the attached information.
By exact hovering, it displays: 65.7mb. The snapshot was taken after the allocation, during the break point.
The data is not found on the heap. The heap only owns 20mb, only having a small instance of 520 bytes as sf::RenderWindow.