The post carries every single note with it, whether it's a like or a reblog. There is also an option on the right in the post dialogue that allows you to put a URL as a 'source'. You could post something and I could reblog it and put my URL as the source, but in the notes, it would still say you posted it. The whole source…
If you use it as a portfolio site, you will be uploading the image yourself, so if people do reblog it, your link will be listed in the notes. You can also put your URL as the source, which is carried throughout the reblogs(unless someone removes it, adding your URL to the image would be better). In order to see the…
oops, only just read this properly - with regards to the layouts and and text, etc - it's all in the theme. You can find themes that change the size of images and text(plus there's some control in the customisation page), plus they change the layout, how things are displayed, whether notes and reblogs are displayed, etc…