I have high standards when it comes to professionalism at work, including dressing professionally while working remotely, but not all my colleagues share the same standards.
Elaine Varelas provides guidance on how you could approach this situation and how to find out what is appropriate attire for your team meetings.

Q. I work remotely on a team in which many of my colleagues live on the west coast. Despite the time difference, we still have many internal company meetings where those west coast colleagues need to start early at 6 or 7 am. The thing that is horrifying to me is that several of them attend the meetings in their pajamas! Obviously, it’s just the top up, but still. I always make it a priority to look polished and professional for our meetings. I always wear a nice professional top. Am I silly to be bothered by this? Can I ask my manager what our “dress code” is for meetings?
A. So, every company has its own culture, and what’s considered casual at some organizations would never fly in more conservative industries. Banking compared to high-tech are great examples of organizations who define their dress codes significantly differently. Remote work has certainly blurred some lines between professional and personal life, and this is one example. While some colleagues might think that the people on the West Coast who show up in their pajamas should be getting awards for just showing up when the meeting is so far out of their normal work hours, it sounds like you’ve got an issue with what these pajamas look like. Now, if you’re talking about a negligee that’s significantly revealing, I might take issue with that. If we’re talking about long sleeve or short sleeve, collared, what could be shirts, then maybe you’re more formal than other people in the organization are.
You can absolutely check your company’s handbook to see if there is anything in there on a preferred dress code, but it might only be focused on those working in the office and may not address virtual meetings. You could also bring this up with your manager or HR and express how you don’t feel comfortable during these meetings when your west coast colleagues are so casual.
Gen Z now considers pajama pants streetwear, and almost any generation now considers yoga wear or athleisure wear ready for public consumption. Not all of us agree that these are the clothes that we’d like to have in our professional world, but if the managers aren’t taking issue with how people are presenting themselves, you might need to be a little more forgiving about how people are showing up to meetings. If you find it offensive, or if there are customers or clients that are going to be at this meeting, or very senior leadership who would also find it offensive, a conversation needs to be had to alert attendees that how they’re dressed is fine for in-house casual meetings, but not appropriate for standard meetings during work hours, and that they need to elevate their game.
The people who are in their pajamas may not recognize that they could be short-circuiting their opportunities to grow and be recognized within the organization, because of what’s perceived as their unprofessional demeanor. Anytime you’re at work, you’re being judged, whether you think you’re taking a break, whether you think you’re having a meal, whether you’re walking between places, whether it’s colleagues or managers, people are assessing just how seriously you take your career. And those who present themselves as taking their career seriously will frequently be given more opportunity than people who don’t present as caring as much about their professional presentation or professional demeanor.