It actually isn't "everything you need to know", because this is straight-up misleading. You've removed the two candidates to the left of Pence (Christie and Hutchinson) who did not raise their hands when asked if they would support Trump as the nominee.
Because it's irrelevant. The point is that 6 candidates raised their hands. Which not only includes those leading in the polls behind Trump but also Mike Pence himself!
What is being comunicated in the image is that every republican nominee says they will support Trump. That is simply a lie; and the image was cropped specifically to make that lie.
The cropping is not accurate to the question asked at the debate, but every candidate there signed a pledge to back whoever wins the GOP primary, and right now that includes Trump as an option.
So for Hutchinson and Christie, the only way this image is not an accurate representation of their stances (if not how they answered the question on stage) is if we assume that they were lying when signing the "loyalty pledge" document that was a requirement for even being on the stage at all.
Christie in particular opposed Trump in the 2016 election....all the way until Trump got the nomination, at which point Christie became an ardent Trump supporter. I think it's reasonable to assume this is a repeat of that track record on his part.
You're making an assumption. I'm the one who made this image and I did not crop it specifically to "make that lie." I cropped it to show the six people that were holding their hands up.
If someone is coming to a political meme community looking for accurate information, let's all be good stewards and direct them to actual reputable news sources.