"I'm coordinating the program for the [Conference Name Removed] conference next month. We include bios and pictures of all the speakers in the program - not unusual. However more than 1/2 of the speakers did not send us a decent picture on their initial submission. Examples: low-resolution (OK for web but not for print) versions, very casual snapshots, or a bad crop out of some picture with other people still included in it (no, I am not kidding). This is taking a lot of extra time for us to go back and request better pictures to try and help them be reflected professionally in the program.
Advice - anyone who wants to be considered even a semi-professional speaker should have a decent print-quality picture. Doesn't need to be a professional headshot, but needs to look business-like and be at least 300 dpi equivalent.
You would think this would go without saying, but apparently not."
If you are speaking at conferences even on occasion, this is important advice!
Have A Great Day.