The only thing you can do is look at reviews. Even then there's really no 100% guarantee you're getting what you see in the picture. There can be multiple versions of an item by different sellers, using the same pictures for listing. A lot of the listings are copies of an original item that's in the picture. A lot are just photoshopped straight from google images.
Your best bet is looking for long established shops with big sales numbers and good reviews and even then you might get something shitty. Looking for places that provide a lot of pictures of the actual item and proper measurements/sizings can be good too.
Sadly, buying clothes online is kind of a crapshoot in places that don't really have customer support beyond "we'll give you your money back if it's damaged". If it doesn't look like the picture, you can ask for refund too, but that doesn't work sometimes.
Most of the clothes I got from ali were actually okay. Usual fast-fashion quality with some skimping on the seams or cheaper fabrics. But then again I paid fast-fashion prices.