This pull-left thing is more of html. I tried using Markdown but found it's not so good in controlling the formatting. So, I decided to stick with HTML which is difficult for people who are not coder or not familiar with it.
Another thing is you don't need to physically resize your image though if you photo is high definition, reducing the size makes the post faster to load.
Have a look at one of my earlier post to see how I frame and sort of reduce the file size:
Now I show how and why import photos into Microsoft Powerpoint | 我示范如何和为什么导入照片到Microsoft Powerpoint 📷

As for resizing the image display, here's what I learn from another post before.
You can also just put the following in front of your image link https://img1.steemit.com/111x222 where 111 and 222 are the width and height you want in pixels. but its hard to know what height and width you want until you see it posted. For example.

1. 88x88

2. 44x44




Have fun! :-)