To afford you easy organization of media you upload to the site, Facebook allows you to create photo and video "albums." Although you use slightly different pathways to upload photos and videos -- namely, clicking buttons that read "Upload Photos" or "Upload Video" -- it is possible to add your photos to an album that already contains video.
Sign on to Facebook and click your "Profile Picture." Scroll down your page and click the "Photos" button along the left side of it.
Click the name of the video album to which you want to add photos. Click the "Add Photos" button in the upper, right corner.
Browse your computer's hard drive for images, select each of the ones you want to add, and then click "Open." Wait for Facebook to tell you the upload has completed.