G-day WB Yeah your welds are looking good and I can see that it is more full at the top end.
I think there are a couple of reasons for this happening:
One has to do with the change of electrode angle as you go up. Often people have the electrode more square to the plate at the bottom so the molten metal is being punched in. Some new to welding tend to leave there hands in the same position as they traverse up so the angle of the electrode increases the further up they travel. Thus the weld tends to build up more rather than be pushed in. Hope that make sense.
A couple of ways to rectify this is to, if you are using a support for your arms/hands is to move the support up after each electrode or to slide the weld coupon down after each electrode so that you maintain the same electrode angle for each electrode.
Two, the other reason is the change in weave tempo as the weld moves up and the electrode gets shorter. It is really important to be consistent with the tempo the whole way. Some of us old timers would weld with a waltz rhythm i.e. 1,2,3, 1,2,3, 1,2,3 etc, so, weaving at 1 and pausing at the side for 2,3,. the pause at the side (toe of weld) allows the toe to fill a little more thus giving a flatter weld.
So remember to keep the electrode at the same angle (vertically) the whole way up and keep the rhythm consistent. and as Jody says, Get lots of bench time and keep burning them rods.
But your welds are looking good so keep up the good work.