Can the terms of reference contain graphics?

Question

Preparation of terms of reference

Can the technical specifications for the site in the development requirements section contain pictures to visually display how the pop-up window should look like, or should it all be in the design layout?

Answer 1

there is no absolute standard of technical specifications: the depth of detail / elaboration - everything is at the discretion of the customer,
just be aware that the performers can understand something literally and rest against it to the detriment of other parts or the project as a whole