A very interesting approach, using the dovetails in opposing directions to hold pieces together. One issue I have is that there are dovetails/pins cut so that there is short grain across the pins and tails which creates a very weak joint. There are enough individual pins and tails that they probably won’t let go except under extreme conditions but a lot to go through just to avoid using glue, dowels (pins), or fasteners which, by the way, would be the traditional techniques. The other issue is that the upper back piece and the sides have grain that run in different directions through the joint so that expansion and contraction run against each other. There may be enough looseness in an unglued joint so that it won’t cause the back board to split or rip up the joint but it isn’t in keeping with traditional practice. One way to correct the short grain issue would be to reinforce them with dowel pins. I normally don’t like dowels because of the end grain glue failure issue with them but this might be an acceptable use for them. Really good effort though. I really like the overall look of the piece.