On the Folksy front page the 2nd section down is " Theme of the day". Each month Folksy release a list of themes for every day of that month, which you can find here in the forums (here is August’s list = Homepage themes and tags for August - here's the list).
When you list an item there’s a section for you to put tags, and the theme of the day uses these tags. So on 24th August the theme will be “seaside”. Any item on Folksy that has the tag “seaside” will be included in the theme of the day section. You only see 8 items at a time on the front page, and these are selected at random (it’ll change every time you refresh the page), but if you click “see more” you’ll see the full list of items.
This thread is asking whether capitalisation matters, so if “seaside” is the theme and you had “Seaside” in your tags, would your item still be included (yes).
However, ignoring upper/lower case, the word does have to match exactly. You have some glass fish which would fit the theme, but they have the tag “by the seaside”. The Folksy system won’t recognise this as a match for the theme of the day, so it won’t get included on the 24th. If you change one of your tags to just say “seaside”, then your fish will have a chance of being on the front page that day