If it is an I phone you can send the picture to your email and then it will ask what size. I have found that the forum accepts medium. Hope this helps.
When you click the button to upload an image you'll see a note that says "Upload a File (Max 1.3 MB):". The average phone pic these days is easily in the 2-3 MB range (or more, depending how you set up your camera). The image posting guideline are here: https://www.yachtforums.com/threads/yachtforums-rules-directions-guidelines.8024/#post-50790
I have been taking screen shots of my photos to use here. The screen shots are small enough files to upload.