Is is an inside shot of Their fence, as pictured in the previous photo.
Here you can see the toe-nail clearly. While toe-nailing a board can have a fairly neat look to it if properly implemented it can tend to split the wood when a ninety degree toenail is attempted (which is the typical angle of a 2 x 4 to post attachment). And rarely if ever has the clean look of using brackets.
Here you can clearly see that this toe-nailing attempt was poorly done at best. The nails can clearly be seen protruding out from the 2 x 4 backrails, which was typical of the job in whole.