So this is going to sound a little weird, and maybe a little out there, so buckle up.
Just a few hours ago the official Twice Twitter released the third video without a caption that seems to be hinting at the next comeback. The first teaser is of the TWICE logo with the hashtag "Finally", the second is of a hand and the hashtag "Fever", and the third is of a fingerless glove with gems on it with the hashtag "Fabulous". (All videos are available on the Fabulous page)
So, what does it mean?
Here are some fan-theories:
1) It is the 'Fabulous' comeback, and that it will probably be their next mini album.
2) There will be three physical copies of the album. Version A will be called Finally, Version B will the called Fever, and Version C will be called Fabulous. (Similar to the Signal EP, with its three different concepts/albums)
3) The theme of the comeback will be partying. The first teaser, Finally, uses a bright neon logo, almost like one you'd find at a club or a bar. The second teaser, Fever, uses the iconic rock & roll hand sign, which is commonly used at concerts/clubs with live music by the audience, to show that they enjoy the music. The third teaser, Fabulous, shows a glove covered in gems, almost like the kind of glove someone would wear to a party or a club. Not something you would wear to the grocery store or to a baby shower.
4) The gems on the glove in the Fabulous teaser represent the members of TWICE. Each gem corresponds with a member of TWICE's individual colors, and since there are nine gems, it kinda makes sense. The butterfly-shaped light blue gem would represent Nayeon, the circular green one would represent Jeongyeon, the rectangular pink gem would represent Momo, the triangular purple gem would represent Sana, the circular orange gem would represent Jihyo, the flower gem with the turquoise center would represent Mina, the white teardrop-shaped one would represent Dahyun, the rectangular red flower gem would represent Chaeyoung, and the oval-shaped dark blue gem would represent Tzuyu. This one makes the most sense to me, especially since Twice just released Lovelys for all the members, and promoted the idea of colors and emotions representing each member of the group, and that each member is unique in their own ways (each of the gems are different shapes and sizes, no two are the same).
Again, these are just my theories. We'll just have to wait and see if this is true or not, but what do ya'll think?