regression - How do I explain the line of best fit in this diagram? - Cross Validated

I teach an intro statistics class at my university (as a graduate student) and I was scouring the internet for interesting graphs on the history of linear regression when I came upon this picture

Linear Regression in Machine Learning [with Examples]

Multiple Linear Regression Fundamentals and Modeling in Python, by Kerem Kargın

Cross-validation pitfalls when selecting and assessing regression and classification models, Journal of Cheminformatics

Simple AutoML for time series with Ray Core — Ray 2.9.3

Recommendations and future directions for supervised machine learning in psychiatry

2.2 Line of best fit STM1001 Topic 8: Correlation and Simple Linear Regression

Partial least squares regression (PLSR) & age prediction. 10-fold

Line of best fit (Linear regression) over vertical line - Cross Validated

Tutorial 1: Linear regression with MSE — Neuromatch Academy: Computational Neuroscience

Cross-validated Gaussian process regression (GPR) model - MATLAB

Calculating a Least Squares Regression Line: Equation, Example, Explanation

Using cross validation to assess interpolation results—ArcGIS Pro

4. Regression and Prediction - Practical Statistics for Data Scientists [Book]