Yes, it is easier in Vectorworks because there every 2D element is also visible in 3D. This is not the case in ARCHICAD.
What you can do: use the "Picture 19" GDL Object. Activate the Object Tool and at the top of the left pane search for "Picture", then select the "Picture 19" Object.
Set the Width and Height (not the Depth - see image) to the model sizes of your city map picture (e.g. 120 m by 200 m). Set the "Tilting angle" parameter to 270 degrees so it will lie horizontally instead of hanging vertically. Set the Frame Type parameter to OFF.
Check the "Use Custom Picture" checkbox. Then you will have to specify the name of the image file in the "Custom Picture Name" field.
But before that you will need to load the image file into your project.
OK the Dialog, place the Object, it will be placed with a default picture.
Go to the File\Libraries and Objects\Library Manager Dialog, click the down-pointing arrow portion of the long Add button at the top and use the Browse for Embedded Objects command. Find your image file and load it. It will be listed under Embedded libraries, which means it will be stored as part of the project file. OK the Dialog and go back to the Object Settings Dialog, where you will now be able to select this image file in the "Custom Picture Name" field.
Now that the Picture is using the correct image all you need to do is set the sizes of the Picture correctly so it matches the the model sizes shown in the image.
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