That's true. But it's not likely anyone is going to sit and study any particular photo for longer than 1/16th of a second. However long it takes to press the little heart icon is about as much investment well over 99% of photos receive on Instagram. If you're lucky, someone comments.
My Instagram account is what's known as soft-blocked. Apparently, if you keep using the same hashtags for your photos, which I was doing, Instagram stops feeding your images through hashtags. So, other than for my meagre number of "followers", my images are roughly not visible. You can check by posting an image and then using someone else's account to check the hashtag.