Breakdown of Me molesta cuando alguien mira el móvil en la videollamada.
Questions & Answers about Me molesta cuando alguien mira el móvil en la videollamada.
Because molestar often works like gustar.
In Me molesta cuando alguien mira el móvil en la videollamada, me means to me, and molesta means is annoying or bothers. So the structure is literally:
To me, it is annoying when someone looks at their phone during the video call.
The annoying thing is not me. The annoying thing is the whole situation.
If you wanted a structure closer to English I am annoyed, you could say Estoy molesto if you are male or Estoy molesta if you are female, but that is a different way of expressing the idea.
It is singular because Spanish treats the whole situation as one thing.
The idea cuando alguien mira el móvil en la videollamada is understood as a single event or circumstance that bothers you, so molesta stays in the third-person singular.
Compare:
Me molesta llegar tarde = Being late bothers me
Me molestan los retrasos = Delays bother me
In the second example, los retrasos is clearly plural, so the verb becomes molestan.