Hi @artist01, I can help answer these questions.
1. When you click REPLY, you will see a grey button Photo/Files. Click that and upload your picture.
2. Use the @ symbol and start typing the member's username. After the first 3 letters, you will get a selection of names to choose from that match. I find it easier to copy the @username of the person I wish to mention.
3. Use the daily digest to see a summary of the day's posts for the groups that you follow. Read more about the daily digest here:
- The Mayo Connect Digest: How to make to most of it https://connect.mayoclinic.org/page/about-connect/newsfeed-post/the-mayo-connect-digest-how-to-make-to-most-of-it/

See more tips here: https://connect.mayoclinic.org/get-started-on-connect/