I mean she is an Apple user, so creating a software that even someone like her will understand is not possible.
Jokes aside, there are users that do not often work with any software and then fail to understand how things work on their own. In the video you see he doesn’t manage to find the right arrow button to flip the page and thinks that it’s a premium feature to be able to scroll down further. I don’t think it is possible to address this by changing the pages design. Some users need to be shown how the software is used. This could be done through a tutorial or a youtube video, but it needs to be clear and slow paced.
Some things on LingQ are however actually not clear if nobody explains them to you.
The translations for lingqs is one of these things. I didn’t know that the suggested translations come from the community when I started, and then I made a post where I reported that some words don’t have a correct translation. I then received a reply that i can use the dictionaries to add my own if the community translations are wrong. This is something that could be mentioned somewhere in a sentence.
Same goes for the content. A user that starts with something like russian will see an almost endless amount of content, where someone starting with Afrikaans has like a few YouTube imports and that’s it. This is also something that could be explained somewhere.
Also it’s clear that she reached the 20 LingQ limit before remotely understanding how to actually use lingq.