Interior blinds create a convection current around them. They catch the sunlight that makes it through the window, get hotter, cause the air between the blinds and glass to rise, and pull in cooler room air from underneath.
Most modern windows have infrared-reflecting coatings, but it works both ways. If it reflects 90% of the infrared away, 10% gets in. Say you have polished aluminum blinds for 95% reflection, it's reflecting 9.5% of the original light back to the window. But then the window reflects 90% back again, or 8.5%. Then the blinds reflect again... All the while, it's finding any gap and heating the materials and air. So yes, blinds help, but it's best if you can keep the heat outside entirely.
I watch outside air temp closely and do open windows once ambient swings past what I want inside. Problem is, outside hasn't dropped below 75f/24c in about 5 weeks here. Most of the inhabited world has this issue in the summer unless it's a desert. Hell, that range is about what I saw in India during winter.
They didn't ask what the comic was, they asked "but why not both?". It can be both unethical and a lesson