more garden work and a question

I completed what I started yesterday, moving the blocks for my herb plot from the shadows to the light. It was a good workout, to be sure, and I am sure the herbs will love the sunlight, but exhausting as heck. Thank goodness it was partly cloudy with a little breeze at times. I am temporarily using it as a compost bin , putting both greens (leaves, grass,etc) and browns (twigs, vine cuts, rose cane trimmings, etc) into it and over the fall and winter will hose and turn it to help break down the plant matter into good compost soil. I have basically oregano and mint remaining of the herbs originally planted there, and they will spend the off-season in pots until spring when I will plant more herbs. I might put some winter pansies there for color or try some winter weather stuff as cover crop. For now I am resting from my labor, and waiting for more tomatoes to ripen.

here’s where the herb plot was:

and this is what it looks like now :

a quick question – does anybody know what this is:

The nobs are on my yellow grape tomato plant, which is in a pot on the patio. (sorry for the fuzzy pic:( ) I have a similar pot with cherry tomatoes, similar growth pattern (in a cage, plenty of tomatoes) and I have been watering them the same , but the cherry tomato plant has no nobs. Is it something to worry about? I had a Roma tomato plant years ago that got blossom-end rot that destroyed all the tomatoes. I learned since then to make sure the leaves don’t have wet contact with the ground -which neither of these do. I expect to harvest a lot from this plant once they ripen. Is there something I can do to fend off any potential problem, or am I just worrying needlessly?
thanks :)