For those who do it to take pictures and post it on social media to get likes and be in good image it does not worth because it is very bad and not respectful to help charity and make shows on it.
If someone want to help charity he/she should not embarrass needy people and post their pictures on social media
For those who volunteer i encourage it because they sometimes help in some cases in charity organization other than giving money. For example , they help in coordination , paper work, renovation , and other things