Looks like a betta cube they sell in walmart for $10-12. It's .3/.7g. For $10 you can get a 1 gal with filter and light :)
Would use the half rounded marbles they have there and in crafting stores for the bottom.. easy/quick to clean and no sharp edges for their fins to drag across. A small cave and a small plant or two.. hard to tell since unsure just how big your tank is.
But yeah, if somehow you can get a small cave in there, I'm sure he'll love it.. Xander loves to go in his cave and just sit there with his head poking out watching his neighbor hehe.