I agree, very nice, Vic.
However, if I may: I can't tell if it is the pics, themselves (distance), as to why I can't see clear details, but I'll assume the edges of the seat upholstery are a little uneven.
When upholstering dining chairs, don't pull the fabric over and under the edges of the seat with your thumb and index finger. That will always result in indentations, or an uneven edge, along the edges.
Preferably, the bulk of the padding should not overlap the edges of the seat base (board), for a fitted seat as that (It looks like the seat fits into/inside the chair framing). Too much padding on the outer edges can cause problems with (pressure on) the chair frame. Be careful with that outer edge padding, that way. A light amount of padding, like a polyester batting (polyester fiberfill), is okay to overlap the edges with, to dull any sharp edges of the board it's on. Just don't use a lot of batting (bulk padding) on the edges.
Application of the fabric: To start, tack or staple (I use staples) the centers of the front and back. The tension, here, shouldn't be the final tension. Somewhat align the sides' centers, but not tight, and tack them in temporary position.
Align the front edge of the fabric, next to the first staple, and staple the adjacent areas, one on each side of the first staple.... staples about 1" apart. If the fabric seems to align easily, staple one more, each side, again. Make sure the lateral tension is good and firm (the finish tension, laterally). Don't pull the fabric, laterally, with your thumb and index finger... use the palm of your hand to pressure it laterally. Work it a few times, with your palm... you'll see the results as you work it.
Now you want to attach the center section of the back edge to its finished tension. Instead of pulling each area with thumb and index finger, place your whole hand on the seat's top and pet (like petting your dog) the "whole" toward the back. The whole of the fabric will adjust itself to conform to and over the edge, uniformly. With your whole hand still in pressured position, remove the initial staple, while using your thumb to hold the fabric in position at that point, then insert a replacement staple, there. Use the petting motion for a few more attachments at the back edge.... and don't forget about the lateral tension, there, also.... , then....
Go back the the front edge and attach another few staples along the front edge. At this point, the front edge conformity can be established with the whole-hand petting motion, also. Just make sure your lateral tension continues to be good and firm/tight. Then repeat the back edge procedure.
Except for upholstering right at the corners, when the front and back edges are done, attach the side edges. Do the same petting procedure for attaching the sides. This petting procedure eliminates awkward, excess and/or contorted fabric gathering at the corners, as often happens when one tries the "thumb-index finger" pulling technique, for stretching fabric across an area.
The petting procedure and the firm lateral tension will help eliminate those dips, valleys, uneven edges. I don't suspect you have too much padding, along the edges, for it to have caused the rippling I think I can see (again, I'm not sure I am seeing correctly). I suspect it was the way the fabric was attached. This petting procedure is a must for fabrics with lines or other similar patterns, that need to be perfectly aligned and uniformly tensioned.
Sonny