Ann: Change of Director's Interest Notice, page-3

It says "No. of securities held prior to change" - 12,158 Fully Paid ordinary shares

then is says "Number Aquired" - 12,158 Fully Paid ordinary shares

then it says "No. of securities held after change" - 12,158 - it's still 12,158 Fully Paid ordinary shares

shouldn't the total now be 24,316 shares? 12,158 + 12,158 = 24,316

Should it not be either be 0 shares held prior to change so now the total held is 12,158 shares

or

24,316 shares held after change - because Sara had 12,158 shares prior to change buying another 12,158 shares bringing her total up to 24,316 shares

What am I not reading right here?