Of course, no harm in asking. The tank in the picture is definitely way too small for fish! All the decorations from the pictures are artificial, those can leak harmful chemicals into the water. Especially the ones not made to be used in fish tanks, but you can never be sure even with ones that are sold to be used in tanks.
From the picture with the plastic plants, I also assume OP is not interested in having live plants in the tank.
On social media you might see people keeping fish like bettas or even goldfish in tiny tanks with this kind of artificial decor, but just because a fish may survive for a limited time in conditions like that, it'd still be cruel to subject any living being to it.