Direct link: https://www.neopets.com/neopies/ (you need to be logged in already)

Voting takes all of one click and you’ll get a prize for participating. Normally the prize pools are pretty much trash, but this year, Jellyneo lists stuff like Marbled Draik Eggs, Valentine Paint Brushes and similarily rare/expensive stuff as possible prizes, so it can’t hurt to try your luck ;)

PS: also don’t forget to collect your February Freebies here: https://www.neopets.com/freebies/index.phtml