I've seen a lot of posters recently say they did not know how to upload a photo from their cell phone into a bunker thread. I'm going to give you the steps for how I do it! I have an iPhone 5 but it should work similarly for any type of cell phone.
1) First things first, download the Photobucket mobile app (there is one for both Apple and Android. Sign in with your account, or create an account if you do not have one.
2) Hit the "Upload Media" button with the arrow pointing up and then hit the button "Choose Existing" to use a picture you already have stored in your photos on your phone.
3) (For iPhone) select "Camera Roll" and select the picture you would like uploaded to your Photobucket account. As soon as you hit the picture it will automatically upload it to your albums.
4) Select the "My Albums" button on the bottom of the app.
5) Tap the photo you just uploaded and hit the "i" circle button at the bottom right hand corner of the screen.
6) Next, tap the html link you see next to "Direct". You phone will give you a message that it has "Copied Direct URL".
7) Open the Bunker in your internet browser (I used Google Chrome). Select the thread in which you want to post the picture, or create a new thread.
8) In the message box type "Paste". Your image URL should now be posted next to HTML code you just typed. Directly at the end of the URL you just pasted, type ">
9) Hit enter and you should be able to see your image you just posted!