Yup. When you click 'reply' to a thread, a box opens up to type your reply. Near the bottom of that box are two buttons; 'Add Files' and 'Other Media'. Click 'Add Files' and it will give you choices from which to retrieve your photos. Choose 'Photo Library', and it takes you to your photos on your phone. Tap the photos you want to post, and on the upper right (at least it is on my iPhone) click on the word 'Add'. That will upload them to the area at the bottom of the reply box, with the word 'Insert' at the lower right of the photo. Click 'Insert' to post your photo to your reply.