In Jainism, the main issue is not the photo itself, but the attachment and possessiveness behind it.

So the simple answer is:

• If there is truly no attachment, no possessiveness, and no ego involved, then it is not a sin in the strong sense.
• But if wearing it creates even subtle attachment, remembrance with craving, pride, or emotional dependence, then it is a form of attachment.

In Jain view, absolute zero attachment is very difficult in practice. Love and respect for your mother are natural, but Jain dharma encourages you to keep them free from bondage and clinging.

So for a normal householder:

• Wearing it out of pure respect is not a grave sin
• But it is still better to remain aware and detached

The Jain ideal is to remember your mother with respect and gratitude in the mind, while minimizing worldly attachment.