Does it fit in with the other episodes yes. Many it is just as enjoyable as the other episodes. Is it worth watching compared to the other episodes moments, not really. It's a bit of the usual between the characters and it's also a kind of expected special/ova like with any series it isn't anything original or the characters that differently like some shows I know of that do make it a fun spin for an OVA/Special/Filler episode. I think Tawawa S1 and 2 OVAs did do it a bit better though. That Tawawa DVD scene in S1 OVA 2 is the best over any beach episode likeS2's OVA or any other short length series.

Spoilers:

In short it's an onsen bath/bit of dinner with everyone and a memory of the pool briefly. That's about the easiest way to sum it up. So not missing much and saved 5-6 minutes.