Helen
There can be several reasons for double potting, whether for showing or not, and bulbs or other plants. For difficult to grow plants it may be so that the roots are not disturbed, or to stabilise the watering regime, and they are permanently grown that way. Usually both pots are visible.
You may not be aware with showing that plants are double potted as the inside pot is buried. Pots in clay often look better even though the grower may grow most of their plants in plastic. Look at the pots, do they look too clean, are they dry all over, is the bottom wetter than the top? These can often indicate if the plants are growing in the show pot.
In a group of 3 plants you may want to just balance up the group pot size so they look similar.
If you grow bulbs like Ian with lots of bulbs in a small pot, but would like to show it. Just drop it into a larger and cover with grit, cutting off the rim of the inner pot with scissors if necessary. Plastic is cheap. A larger clean pot will often make a so so pot look much better.
