If you use the attachment feature, there are size limits.
The box that comes up gives the sizes allowed.

What I do is put my digital pic into the graphics program and resize it to
about 800 x whatever pixels. I save it to a jpeg and use it in that form
to put up here.

If you make a photobucket account for free there at photobucket.com
you can link to any size picture there for free (with some monthly size use
restrictions)..

It is really a task you have to DO to understand.

For attachments here, you browse your files, and select it and hit open, and it goes into the box here. Then you hit upload, and it is done.
But size is important.

I have HP photo too, but I don't use it, sorry.