so what’s the difference between posting a photo and embedding a photo?
posting a photo is just putting a photo in from your computer. click the upload/insert button just above the text box when making a new blog post and upload the photo from your computer. like this one
to embed a photo, get the link of the website where you’ve gotten the image from and in this little line of code in place of “URL”: <img src=”URL”> like below.
<img src=http://imgs.tuts.dragoart.com/how-to-draw-pikachu-gangnam-style_1_000000013943_5.png>
if it doesn’t work (like it didn’t for me the first time i tried) go to the HTML tab (not the visual one) and make sure that the start of your link is a < not < and the end is a >  not a > and you should be good to go :D.
and there you have it.
and now you also have pikachu doing gangnam style