Hey I have this bag in canvas. Bought it at Marni outlet. I also work in fashion so take that for what it's worth.
Muslin storage and label looks same as mine. The label should be embroided grosgrain. It's more expensive than a woven label. But this in itself is not so expensive and easy to fake.
The oval handle looks the same as mine. The way they constructed the handle is kind of tricky in terms of sewing. But not impossible for a good knock off factory---But it would be a really good factory that can do this tricky sewing not a mass production type factory.
Marni in general doesn't use special hardware so the hardware is easy to fake. Sure sign of fakes is the quality of leather which you can not tell from the pictures. In general most fakes use cheap leather. In my work I know that some designers buy leathers from Italy and send it to China for sewing. So for fakes they can never get the cost of the materials low enough to make it worthwhile.
That big leather foot should be made from a thick English bridle type leather. This kind of leather is expensive.
You can also check the zipper. I don't have my bag here but usually a brand like Marni would probably use a good zipper like Riri, Lampo or YKK. YKK is weird because they have good zippers and bad ones. But again it's hard to tell unless in person because the good zippers slide easily and bad ones do not. Some brands like Balenciaga just use Lampo's pull but Marc Jacobs uses their own pull.
I've never seen a fake Marni in NYC so that's a good sign. The brand is not that popular here even though, personally, I love it.
The pictures are so bad that it's hard to tell. I would say it looks real but I can't say for sure.