Use the Image viewer from the Appstore ?
At first sight, I guess there are different ways to insert an entity image on forms.
If you want to develop a solution without leaving Mendix, maybe you want to build an image libray with an "Entity" attribute (String), and retrieve it on your form.
If you are prepared to play around with CSS, there is also the option to refer to a a CSS style in your form. If you refer to static images, this could prevent from consulting your db as I presume that is why you ask to avoid Microflows. It has disadvantages, just like every choice in life... You might need a deploy for any image. To avoid this, you may replace the image file manually, you will need to be sure to maintain this in future deploys, and think twice before giving up the fully automated Mendix deploy process.
Do you have a preference? (or are there other people seeing more options at first sight?)
Hello Do you just want to an image viewer which can use on a dataView to display an image without calling an microflow?Although i am not so good at this,But i know there is an image windows viewer which is powerful enough for you to view images.You can have a look.