A “standard” headshot shows the actors face & should represent who he/she is. It’s you on a good day. It gives the viewer an essence of who you are. You can see the actors eyes well. (That’s where the communication comes from.)
Chopping off the top of the head is just a style. In some cases it works & in some cases it looks ridiculous, (chopping too much). The reason it can be popular with photographers is that it puts emphasis on the eyes and can place the eyes in the top third of the photograph which follows a composition rule. Apparently it upsets some people to see this, but at the same time many love that look. It’s really just a matter of opinion & hopefully the photographer doesn’t go to far.
As a photographer I’ve always seen agents choosing both styles (chopped & non-chopped). The headshot trends that are popular with agents that I’ve seen & received feedback from are:
1. Tight or close-up shots, which make better thumbnails.
2. Natural light
3. Natural make-up
4. Natural hairstyles (not glamourized)
5. No make-up kids (tinted Chapstick or a slightly popping the eyes is okay.
6. Character or personality shots using good expressions. You can vary with a slightly suggestive wardrobe. Don’t over do it. Example argyle sweater can be used for the “geek” shot.
7. Brighter colors that “pop” online.
The opinions with headshots are many. I believe an actor should love his headshot (otherwise a lack of confidence in passing it out), but also trust their agent picks. You do want your agent to be happy with your headshot, because you want them to be enthusiastic about sending it or submitting you. These days we are so lucky since you can have more then one shot online.
The standard for updating your headshots is when you change. (Hair color, weight, age, kids teeth etc.). Also, new headshots can generate interest if yours have become a bit stale. If your headshot is working very well, don’t change it, unless of course it doesn’t represent you well.