I honestly don't think it's too small. Chinese alligators only get 5 feet at maximum, and like all reptiles, are very inactive and slow-moving animals. The real issue IMO is the dwarf crocodile exhibit further before in the reptile house.
@Ebirah766 I found the Dwarf Crocodile and even the Cuban Crocodile exhibits to be shockingly small, especially for a zoo of Bronx's status. Looking at those photos, it almost seems like roadside zoo conditions to be honest. Also, a few other enclosures in the Reptile House (Green Anaconda, Reticulated Python) are very plain and lacking much of anything, but the terrariums for smaller creatures are well done.
@snowleopard
I do think the Cuban crocodile exhibit could be larger. With reptiles, it's easier to just fulfill the basic needs rather than making anything extravagant. Also we have to keep in mind that this exhibit is somewhat older, though that obviously doesn't excuse small enclosures.
@snowleopard I feel that, as is common in many zoos, the Bronx zoo has some "legacy issues"; of course, the reptile house could improve their crocodilians' conditions, but this may be at the cost of species numbers (for example, only keeping the Malaysian gharials and Chinese alligators, with more space for each)