Originally Posted by Reminosys

Definitely fake. Bananas and shallots aren't closely related enough to graft, so the shallot wouldn't be able to transfer nutrients into that sliver of banana. If it were a case of using naturally occurring plant hormones to encourage the growth of the banana seedling it might make more sense, but then there'd be no reason to bury the shallot alongside the banana piece when you could just rub some of the juice on.

If trying to get a plant to grow from banana flesh, it'd take a significant amount of bioengineering to revert specialized fruiting body cells into a stem cell state. Might be possible with other kinds of plants, but it's typically a very labor intensive process done in lab conditions.

Take a look at the soil towards the end of the second vid as well, it looks too fresh to have been sitting around long enough for that seedling to grow to such a size. If the soil had been undisturbed, it would have gradually become duller in color as the organic matter decomposed. They probably did a bait and switch with the plants in the pot.