If you want to tag people on Twitter but are worried about the character count, ???????? might work. You can tag up to 10 people on the image. However, their settings should allow people to tag them in images. If a person has disallowed it, you won’t be able to tag them in the image.
Take a call on how important it is for you to tag that person. You always have the option to tag them as a part of your tweet.
If you have any questions, feel free to ask.
Have a socially profitable day. 🙂