Pictures on your phone are saved as data files (JPG), which you can retrieve using a computer and save in a different location. You can also email the photo to yourself, and retrieve it that way. In any case, the photo needs to be stored on a computer in order to attach it to a thread in this forum. (Some forums require it to be in a dropbox site, like Shutterfly). I don't know any way you can do it directly.
iPhones are particularly easy. Set up an iCloud account in your computer (automatic in a MAC), and you can copy or use them without downloading. (You can't save anything to iCloud from a PC, only read or copy.)
I make it a practice to save phone photos to the computer. That way they're (relatively) safe from accidental erasure. That's important for cute moments with grandchildren.
I have downloaded pics from my phone onto my computer and then retrieved them later from My Pictures folder. Emailed from phone also. I have never been satisfied with the quality of a phone pic though. I try to always use a digital camera when photographing rifle's for optimum detail and clarity.
Alright after about a year of trying to figure this out I've got it now. Phone browser didn't support it. So I tried dolphin browser. Still didn't work. I downloaded firefox for android and it works just fine. A little slow but posts none the less.