Not bots at all. If you bother to learn about trading you will realise this is CXXT trade
It means in CBA terms, a trade occurred between two clients (which one could be you selling and other buying)
ie A real simple way of looking at it is..... There is 100 Buy/Sell order shares and there are 100 sellers/Buyers of different numbers (but smaller or larger) and the differences are reported to CBA platform
Each line is matched WITHIN CBA - and the shortfall or over amount reported for each line.
These tranactions are not even sent to ASX. And are traded at what ASX share price is.