I think there's a confusion of the difference between showing and telling here.
Tell: Her heart filled with sadness
Show: Her chest tightened, holding back her sobs.
No, that's not the difference. Generally, when people advise writers to show and not tell, they are referring to situations where the author simply tells people about the qualities of something rather than show it, and expect the readers to accept the description at face value even though the later scene contradicts it.
E.g. Tell: "Mary Sue was the most intelligent girl to have existed. She graduated from XXX Academy, had three PhDs, a pilot's license and was a genius who won the Nobel Prize."
Nobody cares about that. Telling us your character is intelligent doesn't do anything other than telling us the author's intention for the character...and then they tend to ruin it by having their characters do something incredibly stupid anyway, which contradicts what we were told. Like Mary Sue swaggering about arrogantly, insulting someone and getting into a fight for no reason. What kind of intelligent person does that?
No, the author is supposed to show how the character is intelligent through the character's actions. Maybe have a scene where Mary Sue is working in a lab. Or have a scene where she solves a problem (maybe she looks at a crime scene, analyzes the clues and identifies the culprit, but don't skip those steps - make sure you have those descriptions).
Another example is this:
Tell: "A war happened here. It was violent and many people died."
Yeah, like we are supposed to care about that when the scene shows a character idly musing to himself in a supposedly wartorn zone (what the f is he doing there?) and composing poetry while feeding birds. Show the violence and deaths. For example:
Private Johnson screamed as he ducked down, the roar of the missile above drowning out his voice. The next second, he found himself hurled forward by a shockwave. As he rolled to his feet groggily, he saw James cut apart by shrapnel, his body disappearing into a mist of blood. Two meters away, Rick staggered as bullets punched through his armor and into his body, doing a slow dance before he collapsed.
Johnson was beginning to regret ever enlisting in the army. The recruiting brochures had never mentioned that war would be so violent, so brutal. They had promised glory and honor. But there was no honor to be found in the battlefield. Only death.
It's all right to tell us what emotions the characters are feeling. For example, Johnson can be screaming in fear - that's perfectly fine. No need to "show" us by describing how his pulse was racing, how he was shivering, how he went pale, etc. That's just descriptions. The point of the scene was just to show the violence, not take it for granted that the audience will listen to whatever you say. I mean, it's not even necessary to show the scene (that was just an example). Having a character step into the aftermath and seeing burned out husks of buildings is more than enough. Or rows of homeless people huddling together. The point is that if you want to tell the readers that the war was violent (example), then make it matter. Don't tell the readers that a violent war happened, and the next scene the character is just strolling through a park of the supposedly wartorn city and feeding birds.
Showing and not telling usually refers to author pushing or projecting their intentions onto the reader and expecting us to accept their statements, only to contradict them later. Like, "Oh, the character is smart. Oh, the war was tragic." But then we don't feel it because the character does nothing in the story to indicate that he/she is smart or nobody seems particularly affected by the war.
But that doesn't mean you need to describe every single thing like emotions, feelings, visuals, images, etc.
