Text popup on a picture, how?

I want a text to appear when I touch a photo, how can I achieve this?

If you mean a tooltip you can activate tooltips in the options panel under Tooltips. Highlight your image in the overview panel and in the options panel under Tooltips enter your text and choose a placement for the tooltip. That’s it.

In addition to using Bootstrap’s tooltips, you can create ordinary tooltips (without the Bootstrap styling) by simply adding the title tag and text to your link via the Attributes panel.