If you want to impress on social media, follow the trends. If you want to impress on a photoshoot or production set among professional peers, learn to express and evoke. Technically, you can do both, but you get the point I'm trying to make. What works on social doesn't necessarily translate to the studio or set. Someone can be great at taking selfies but very stiff and rigid in a professional environment.
One trend that tends to spill over into the studio is a deadpan style of modeling, where they are intentionally trying to be emotionless. While I'm sure there is a time and place for that concept, being multi-dimensional with your expressions will benefit you much more as it will open up additional opportunities. And if you can pose, whew, no one can stop your wave.
You never know what the future holds, so what better time to improve on the basics than now. Actress/model Sophia Loren credited her success with modeling back to when she was a teen and took acting classes where she learned and developed her skills to evoke different facial expressions. (Sophia Loren's story is incredible; she grew up in the poverty of war-torn Italy, where her mom earned extra money giving piano lessons that helped pay for the acting lessons she took. Can you tell I'm a fan?)
O.K., let's take happiness, for example. Sounds easy enough, right? Not so fast because there are subtleties within a happy expression. You can be happy and smile, whereas you can express the same emotion without smiling; you can also be content and happy. Diving even more in-depth, the sentiment behind happiness varies too. For example, going on a date vs. getting married. Both can make someone happy, but the energy behind them is different and will manifest itself in different ways. Pick any emotion, and you can find variability in which to express with. The more comprehensive range you can perform with, the more value you bring to your industry.
If you think about it, we all non-verbally express ourselves daily. In public, with friends, family, and strangers, we communicate with gestures, expressions, and energy without ever saying a word. Since birth, your ability to express yourself in varying ways has been with you. Your job as a professional is to harness that power naturally that looks good on camera, combined with your angles and posing.
Actors obviously have to be attuned to emotional expressions, but so does someone like an illustrator, where every drawn angle of a line can evoke something different visually. Modeling is similar in that there is a theatrical aspect. It's all a show, one big production. The difference is talented people can infuse a truth of themselves into the "show" that makes it genuine.
Just like many photographers are simply "dudes with a camera" only going through the motions without any real direction, others are inspired by what they do, follow their heart, and are internally motivated to do more than just take a picture. What is your motivation for doing what you do? Everyone's goals are different, so there is no right or wrong; it depends on what you really want, but in either case, you will only increase the value you can bring to a vision/project the more layered you become.
All the world's a stage,
And all the men and women merely players;
They have their exits and their entrances,
And one man in his time plays many parts,
- William Shakespeare