You can add images across your Mobilize account to make it branded and personal for your community.
Cover photos (available on Premium and Enterprise) are minimum 690 * 136.
Header photo images are 1200*236. You can upload any photo larger than that, and you'll be able to crop and zoom your photo easily like this:
You can add header photos to each of your group's registration forms. Enterprise users can also add a header photo to your login page.
Logo photo images are 100*100. If you don't have a square image and your logo is getting cropped, here's our pro tip. Use your favorite basic editing tool to combine your rectangular logo with a white square (in Powerpoint you can "group" images together), re-save the image, and then import your new square image into Mobilize. You can add a logo to every group and to your overall network.