Authenticity cannot be settled on a video call. What a show can do is make a seller handle the card while you watch, which a listing photograph never does.
What to ask them to do on camera
Tilt it under a single light. Slowly, both faces. You are not looking for a specific pattern; you are asking to see the surface behind the light rather than in front of it.
Hold it square on, filling the frame, both sides. Photographs taken at an angle hide the edges, and the edges are where condition and trimming arguments start.
Show the edges and the corners close up.
Take it out of the sleeve, if it is not in a graded holder. A seller who will not is worth asking why.
For anything in a graded holder: the label and the case, both sides, including the edges of the case.
What a refusal means
This category has a particular pattern: lots of photographs, all at the same flattering angle. Asking for a different angle is a small request, and a seller who cannot manage it during a live show — where the card is in their hand — has told you something.
"It is in a sleeve, I would rather not open it" is reasonable for a cheap card and not for an expensive one. Decide which this is before you bid.
What this page will not do
It will not describe the print surface of a genuine card, or what a correct holo pattern looks like. Those specifics change by set and by print run, and a buyer who thinks they have verified a card from a general description is more exposed than one who knows they have not.
For a card worth real money, the sensible path is a graded one, or photographs good enough to send to somebody who grades.
What protects you if you get it wrong
A counterfeit card is not as described: returnable for 7 days whatever the store's policy, and reportable.
A trimmed card is the same argument, which is why the square-on photographs of the edges are worth asking for before rather than after.
Questions people ask
Does a graded card remove the risk?
It moves the question to the holder rather than the card, and holders are themselves faked. Ask for the label and the case edges.
Is a cheap card worth all this?
No. Scale the questions to the price — that is the whole skill.
What if the seller is also a collector and clearly knows the hobby?
Then they will enjoy the questions. Knowledge and honesty are not the same thing, but somebody who answers precisely is usually both.
More: spotting a counterfeit before you bid, Metzee's position on counterfeits, reporting a seller, questions to ask before bidding on trading cards.