If it is going to fill out it will just be a couple days later. Don't expect the second ear to fill out two weeks or a month later.

The pictures seem a very nice size for me. I really like your balcony and being able to look out over the garden - the iron lattice work is very nice. I had a small patch of field corn this year that was about 18 inches tall when it was unexpectedly mowed to 3 inches by my goats. It certainly did not do it any favors, but it recovered much better than I expected. It was already planted late, so the result wasn't great ( strangely, I am feeding it to the goats - I have just now realized that they have outsmarted me once more!). To create corn hybrids it used to be common to remove tassels. I am not sure about the timing. Corn is tough! Very nice garden!

23 ears for 20 plants. They look nice. I have read that you can harvest 2 to 3 ears per plant, given good sun, water, fertilizer and adequate polination. My guess is that some of your outside plants did not receive as good polination as the inner plants.

Sometimes the smaller secondary ears do mature and are worth harvesting and sometimes they don't. It just depends on how well the secondary ears pollinated and on how vigorous the corn plants remain, and it even depends on the variety of sweet corn you're growing. The varieties I grow generally produce two good ears per plant, and sometimes even a third small ear lower down on the plants some years. Are you saying you're only getting one big ear per plant and then have a smaller second ear?