Only good for plants...
Being the novice I was when I was about 12 I "rescued" 2 bettas from a Pets Mart and put them both into separate cheap tiny little novelty tanks and that's how they lived for about a year and a half until I bought my third one and put him into a 5 gallon tank. I instantly noticed the difference!
My 3rd Betta was flying all over the place he was noticeably happier responded faster (in a non-aggressive way) when I'd come near the tank and he lived for a little more than 3 and a half years! My other two barely made it to 2 years. They were depressed uninterested slow to respond...everything you don't want your Betta to be. And once I moved them into larger 3 gallon tanks each they perked up like none other!
Betta's need to be in 3-10 gallon tanks by themselves (5 or larger and you might be able to add compatible fish though I wasn't willing to risk it). In the wild they live in rice paddies which are thousands of gallons of swimming space and naturally aerated and filtered and only live in "small puddles" for about 2 or 3 months (at most) out of the year during the dry season.
What's more while Wild bettas may be able to take smaller conditions longer and survive better the fancy bettas we see in the stores today are not nearly as durable or hardy and need more stimulation and space.
This "tank" has no filtration has little space for the Betta and isn't much better than the initial cup they come in. I'd use it for water plants; less cruel and easier to tend to and it would look just as pretty!
For a Betta...no. It's just cruel to confine a fish no matter how small into that sort of an environment for extended periods of time.More detail ...
