There are two separate issues, the iPhone and the pajamas. Either way, it would probably be a bracha levatalah.
The iPhone might be a sensitivity (and that’s your opinion) but it absolutely doesn’t make your davening on a lower level.
The pajamas, if you’re a girl and they have pants, may be an issue. Otherwise, I think you just need to be wearing something, though it’s probably much better not to wear pajamas.