The screenshot you have attached is about the size of the GCPs marker, the size of the GCPs marker should be greater than 5-10 times the pixel size of the image so that it can be visible on the image while marking GCPs.
If your image has the GSD of 2.36 cm/pixel, the size of the GCPs marker should be 5-10 times the GSD so that it is easily visible while marking the GCPs.
However, if you are confused about the GSD of the output orthomosaic as shown in the figure below. 10 times the 2.36cm/pixel means, your orthomosaic and DSM will have the GSD of 23.6cm/pixel. So, if you need it to be 2.36cm/pixel, you have to multiply by 1.